Communication network systems, jamming devices, control devices, vehicles, programs, communication methods

Abstract

To provide a communication network system capable of suppressing communication errors occurring in a specific communication device.SOLUTION: A communication network system includes a plurality of communication devices. The communication network system also includes a management device 50 that transmits a start signal to the plurality of communication devices, and a first communication device 10 which is a jamming device that transmits a jamming signal to jam sensing of the start signal by the plurality of communication devices. After sensing the start signal, the plurality of communication devices communicate using a first communication method in which each communication device transmits data in a predetermined order. The jamming device transmits the jamming signal depending on the status of a communication error in the communication network system. When a state in which the start signal is not sensed continues for a predetermined time, the plurality of communication devices switch the communication method to a second communication method in which data is transmitted when other communication devices are not transmitting data, regardless of the predetermined order.SELECTED DRAWING: Figure 8

Description

Technical Field

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[0001] This invention relates to a communication network system, an interference device, a management device, a vehicle, a program, and a communication method.

Background Art

[0002] Patent Document 1 discloses a communication network system. This communication network system is composed of a plurality of communication devices. The plurality of communication devices includes a management device. The management device transmits a start signal. After the start signal is transmitted, the plurality of communication devices including the management device transmit data according to a preset order for each.

Prior Art Documents

[0006] The jamming device for solving the above problem is applied to a communication network system comprising a plurality of communication devices and a management device that transmits a start signal to the communication devices. The plurality of communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal. On the other hand, if the plurality of communication devices do not sense the start signal for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order. The jamming device transmits a jamming signal that interferes with the communication devices' sensing of the start signal, depending on the communication error situation in the communication network system.

[0007] A communication network system for solving the above problems is composed of multiple communication devices. The communication network system includes a management device that transmits a start signal to the multiple communication devices. In the communication network system, the multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal. In the communication network system, the management device stops transmitting the start signal depending on the status of communication errors in the communication network system. In the communication network system, if the state of not sensing the start signal continues for a predetermined time, the multiple communication devices switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order.

[0008] To solve the above problem, the management device transmits a start signal in a communication network system composed of multiple communication devices. After sensing the start signal, the multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order. On the other hand, if the multiple communication devices do not sense the start signal for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order. The management device stops transmitting the start signal depending on the status of communication errors in the communication network system.

[0009] A communication network system provided in a vehicle to solve the above problems is composed of multiple communication devices. The vehicle equipped with the communication network system includes a management device that transmits a start signal to the multiple communication devices, and a jamming device that transmits a jamming signal to interfere with the detection of the start signal by the multiple communication devices. In the vehicle equipped with the communication network system, the multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after detecting the start signal. In the vehicle equipped with the communication network system, the jamming device transmits the jamming signal according to the status of communication errors in the communication network system. In the vehicle equipped with the communication network system, if the state of not detecting the start signal continues for a predetermined time, the multiple communication devices switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order.

[0010] A vehicle equipped with a communication network system to solve the above problems is composed of multiple communication devices. The vehicle equipped with the communication network system includes a management device that transmits a start signal to the multiple communication devices. In the vehicle equipped with the communication network system, the multiple communication devices communicate with each other using a first communication method in which, after sensing the start signal, each communication device transmits data in a predetermined order. In the vehicle equipped with the communication network system, the management device stops transmitting the start signal depending on the status of communication errors in the communication network system. In the vehicle equipped with the communication network system, if the state of not sensing the start signal continues for a predetermined time, the multiple communication devices switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order.

[0011] The program for solving the above problem is applied to a jamming device for a communication network system. The communication network system comprises a plurality of communication devices and a management device that transmits a start signal. The plurality of communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after sensing the start signal. On the other hand, if the plurality of communication devices do not sense the start signal for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order. The program causes the jamming device to transmit a jamming signal that interferes with the communication devices' detection of the start signal, based on the status of communication errors in the communication network system.

[0012] The program for solving the above problem is applied to a management device that transmits a start signal in a communication network system composed of multiple communication devices. The multiple communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after sensing the start signal. On the other hand, if the multiple communication devices do not sense the start signal for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order. The program causes the management device to stop transmitting the start signal based on the status of communication errors in the communication network system.

[0013] A communication method for solving the above problems is a communication method in a communication network system. The communication network system is composed of a plurality of communication devices. The communication network system includes a management device that transmits a start signal and a jamming device that transmits a jamming signal that interferes with the detection of the start signal by the communication devices. In the communication network system, the plurality of communication devices communicate with each other using a first communication method in which, after detecting the start signal, they transmit their respective data in a predetermined order. The communication method includes the step of the jamming device transmitting the jamming signal based on the status of communication errors in the communication network system. The communication method includes the step of switching the communication method to a second communication method in which, if the plurality of communication devices fail to detect the start signal for a predetermined period of time, they transmit data regardless of the predetermined order, when other communication devices are not transmitting data.

[0014] The communication method for solving the above problems is a communication method in a communication network system. The communication network system is composed of a plurality of communication devices. The communication network system includes a management device that transmits a start signal. In the communication network system, the plurality of communication devices communicate with each other using a first communication method in which, after sensing the start signal, they transmit their respective data in a predetermined order. The communication method includes the step of the management device stopping the transmission of the start signal based on the status of a communication error in the communication network system. The communication method includes the step of switching the communication method to a second communication method in which, if the plurality of communication devices do not sense the start signal for a predetermined period of time, they transmit data regardless of the predetermined order, when other communication devices are not transmitting data. [Effects of the Invention]

[0015] Communication network systems, jamming devices, management devices, vehicles, programs, and communication methods can suppress communication errors that occur in specific communication devices. [Brief explanation of the drawing]

[0016] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a communication network system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of a mode in which a communication device in a communication network system according to an embodiment transmits data using a first communication method. [Figure 3] FIG. 3 is a sequence diagram showing a communication mode by a first communication method executed by a management device, a first communication device, and a second communication device in a communication network system according to an embodiment. [Figure 4] FIG. 4 is a flowchart showing a flow of processing related to data transmission using a first communication method executed by a communication device in a communication network system according to an embodiment. [Figure 5] FIG. 5 is a schematic diagram showing an example of a mode in which a communication device in a communication network system according to an embodiment transmits data using a second communication method. [Figure 6] FIG. 6 is a sequence diagram showing a communication mode by a second communication method executed by a management device, a first communication device, and a second communication device in a communication network system according to an embodiment. [Figure 7] FIG. 7 is a flowchart showing a flow of processing related to data transmission using a second communication method executed by a communication device in a communication network system according to an embodiment. [Figure 8] FIG. 8 is a sequence diagram showing an example of a communication mode when a management device, a first communication device, and a second communication device in a communication network system according to an embodiment switch the communication method to a second communication method. [Figure 9] FIG. 9 is a table showing the status of communication errors in a communication network system, which is acquired by a first communication device in a communication network system according to an embodiment. [Figure 10] FIG. 10 is a flowchart showing a flow of processing related to transmission of a jamming signal executed by a first communication device in a communication network system according to an embodiment. [Figure 11]FIG. 11 is a flowchart showing the flow of processing related to switching to a second communication method executed by a communication device in the communication network system of the embodiment. [Figure 12] FIG. 12 is a flowchart showing the flow of processing related to resuming transmission of a start signal executed by a management device in the communication network system of the embodiment. [Figure 13] FIG. 13 is a sequence diagram showing an example of a communication mode when a management device, a first communication device, and a second communication device in the communication network system of the first modification example switch the communication method to the second communication method. [Figure 14] FIG. 14 is a flowchart showing the flow of processing related to transmission of an interference request signal executed by a second communication device in the communication network system of the first modification example. [Figure 15] FIG. 15 is a sequence diagram showing an example of a communication mode when a management device, a first communication device, and a second communication device in the communication network system of the second modification example switch the communication method to the second communication method. [Figure 16] FIG. 16 is a flowchart showing the flow of processing related to transmission of an interference request signal executed by a second communication device in the communication network system of the second modification example. [Figure 17] FIG. 17 is a flowchart showing the flow of processing related to transmission of an interference signal executed by a first communication device in the communication network system of the second modification example. [Figure 18] FIG. 18 is a sequence diagram showing an example of a communication mode when a management device, a first communication device, and a second communication device in the communication network system of the third modification example switch the communication method to the second communication method. [Figure 19] FIG. 19 is a flowchart showing the flow of processing related to stopping transmission of a start signal executed by a management device in the communication network system of the third modification example. [Figure 20]Figure 20 is a sequence diagram showing an example of a communication mode in which the management device, the first communication device, and the second communication device in the fourth modified communication network system switch the communication method to the second communication method. [Figure 21] Figure 21 is a flowchart showing the processing flow related to the transmission of a stop request signal performed by the first communication device in the communication network system of the fourth modification example. [Figure 22] Figure 22 is a sequence diagram showing an example of the communication patterns when the management device, the first communication device, and the second communication device in the fifth modified example communication network system switch to the second communication method. [Figure 23] Figure 23 is a flowchart showing the processing flow related to the transmission of a stop request signal performed by the first communication device in the fifth modified example of the communication network system. [Figure 24] Figure 24 is a flowchart showing the processing flow related to the cessation of transmission of a start signal, which is performed by the management device in the fifth modified example of the communication network system. [Modes for carrying out the invention]

[0017] An embodiment of the communication network system will be described below with reference to Figures 1 to 12. <Configuration of communication network system 100> As shown in Figure 1, the communication network system 100 is composed of multiple communication devices. These multiple communication devices are connected to each other via a communication bus 30 so that they can communicate with one another.

[0018] The communication network system 100 is applied to a vehicle. The multiple communication devices that make up the communication network system 100 are electronic control units (ECUs) in the vehicle. The multiple communication devices communicate with each other via the communication bus 30 to realize specific functions in the vehicle.

[0019] One of the multiple communication devices that make up the communication network system 100 is the management device 50. As shown in Figure 1, the management device 50 comprises a processing unit 51 and a storage device 52. A program is stored in the storage device 52. The processing unit 51 executes the program stored in the storage device 52 and performs various processes. The processing unit 51 includes a processor.

[0020] One of the multiple communication devices that make up the communication network system 100 is the first communication device 10. As shown in Figure 1, the first communication device 10 includes a processing unit 11 and a storage device 12. The storage device 12 stores a program. The program stored in the storage device 12 includes a program that controls the communication methods of the multiple communication devices in the communication network system 100. The processing unit 11 executes the program stored in the storage device 12 and performs various processes. The processing unit 11 includes a processor.

[0021] One of the multiple communication devices that make up the communication network system 100 is the second communication device 20. As shown in Figure 1, the second communication device 20 includes a processing unit 21 and a storage device 22. A program is stored in the storage device 22. The processing unit 21 executes the program stored in the storage device 22 and performs various processes. The processing unit 21 includes a processor.

[0022] Each communication device transmits data via the communication bus 30 to perform a specific function. Hereinafter, the data transmitted by the first communication device 10 will be referred to as the first data 41. The data transmitted by the second communication device 20 will be referred to as the second data 42. The data transmitted by the management device 50 will be referred to as the third data 43. Each communication device uses the first communication method as the communication method for exchanging data with each other.

[0023] Each communication device does not transmit data when the function it provides is not necessary for vehicle control. In other words, the first data 41 to the third data 43 are not transmitted when they are not needed for vehicle control.

[0024] The management device 50 transmits a start signal 40 in addition to the third data 43. The start signal 40 will be described later. The first communication device 10 transmits an interference signal in addition to the first data 41. The interference signal will also be described later.

[0025] Thus, in this embodiment, the communication network system 100 is composed of three communication devices and one communication bus. The number of communication devices included in the communication network system 100 is not limited to this embodiment. Furthermore, the manner in which each communication device is connected, i.e., the topology of the communication network system 100, is also not limited to this embodiment.

[0026] <Overview of the first communication method> Figure 2 shows an example of how data is transmitted to the communication bus 30 in the first communication method. The rectangles in Figure 2 represent the data transmitted by each communication device. The area of ​​the rectangles in Figure 2 is proportional to the data size. Therefore, in Figure 2, the second data 42 has the largest size. Note that each communication device does not transmit the same amount of data every time. Therefore, although the second data 42 is shown as having the largest size in Figure 2, it is not necessarily the case that the second data 42 has the largest size at other times.

[0027] In Figure 2, the data is transmitted sequentially from left to right. As shown in Figure 2, in the first communication method, a start signal 40 is transmitted first. The management device 50 periodically transmits the start signal 40. The start signal 40 is a signal that informs each communication device connected to the communication bus 30 that data communication using the first communication method has begun.

[0028] When a communication device detects the start signal 40, if it has data it wishes to transmit, it transmits the data using the first communication method. In the first communication method, the order in which each communication device transmits data after the start signal 40 is transmitted is predetermined. This order may be determined when the communication network system 100 is constructed, or the management device 50 may determine the order. If the management device 50 determines the order, the management device 50 transmits information indicating the order along with the start signal 40 and other signals, so that each communication device knows the order in which it will transmit the data.

[0029] In the example shown in Figure 2, after the start signal 40 is transmitted in the communication network system 100, the first communication device 10 transmits the first data 41. Also in the example shown in Figure 2, after the first data 41 is transmitted in the communication network system 100, the second communication device 20 transmits the second data 42. And in the example shown in Figure 2, after the second data 42 is transmitted in the communication network system 100, the management device 50 transmits the third data 43. Note that the order in which the communication devices transmit data in the first communication method is not limited to this embodiment.

[0030] In this way, each communication device transmits data in order after the start signal 40 is transmitted. After the start signal 40 is transmitted, each communication device knows which communication device is currently in the order to transmit data in order.

[0031] In the example shown in Figure 2, immediately after the start signal 40 is transmitted, each communication device recognizes that it is currently the turn of the first communication device 10 to transmit the first data 41. In the example shown in Figure 2, after the first data 41 is transmitted, each communication device understands that it is now the turn of the second communication device 20 to transmit the second data 42. As mentioned earlier, the first data 41 to the third data 43 are not transmitted when they are not necessary for vehicle control. In other words, depending on the function being executed and the content of the information being communicated, the first communication device 10 may not transmit the first data 41. In this case, each communication device determines that the first communication device 10 will not transmit data after a certain period of time has elapsed without the first data 41 being transmitted. Then, because a certain period of time has passed without the first data 41 being transmitted, it understands that it is now the turn of the second communication device 20 to transmit the second data 42.

[0032] In the example shown in Figure 2, after the second data 42 is transmitted, each communication device understands that it is now the management device 50's turn to transmit the third data 43. If the second communication device 20 does not transmit the second data 42, each communication device determines that the second communication device 20 will not transmit data after a certain period of time has elapsed without the second data 42 being transmitted. Then, because a certain period of time has passed without the second data 42 being transmitted, the device understands that it is now the management device 50's turn to transmit the third data 43.

[0033] Figure 3 shows the communication between the first communication device 10, the second communication device 20, and the management device 50 in the first communication system. As shown in Figure 3, in the first communication method, the management device 50 first transmits a start signal 40 to the first communication device 10 and the second communication device 20.

[0034] Next, the first communication device 10 transmits the first data 41 to the management device 50 and the second communication device 20. At this time, the first communication device 10 transmits the first data 41 after it has determined that it is currently its turn to transmit data. Depending on the function being executed and the content of the information to be communicated, the first communication device 10 may not transmit the first data 41.

[0035] Next, the second communication device 20 transmits the second data 42 to the management device 50 and the first communication device 10. At this time, the second communication device 20 transmits the second data 42 after it has determined that it is now its turn to transmit data. Note that, similar to the first communication device 10, the second communication device 20 may not transmit the second data 42 depending on the function it is performing and the content of the information to be communicated.

[0036] Next, the management device 50 transmits the third data 43 to the first communication device 10 and the second communication device 20. At this time, the management device 50 transmits the third data 43 after it has determined that it is currently its turn to transmit data. Note that, similar to the first communication device 10, the management device 50 may not transmit the third data 43 depending on the function it is performing and the content of the information to be communicated.

[0037] <Processing performed by the processing unit of each communication device in the first communication method> Figure 4 shows a series of processes performed by each communication device in the communication network system 100 in the first communication method. The first communication device 10, the second communication device 20, and the management device 50 each perform the processes shown in Figure 4 after recognizing that it is currently their turn to transmit data.

[0038] This series of processes is performed by the processing units of each communication device in the communication network system 100. Specifically, this series of processes is performed by the processing unit 11 of the first communication device 10, the processing unit 21 of the second communication device 20, and the processing unit 51 of the management device 50, respectively.

[0039] First, let's explain the flow of the processing unit 11 of the first communication device 10 when it performs the series of processes shown in Figure 4. As shown in Figure 4, once this series of processes begins, in step S11, the processing unit 11 determines whether or not it has data to transmit. In other words, the processing unit 11 determines whether or not the first communication device 10 needs to transmit the first data 41.

[0040] In the process of step S11, if the processing unit 11 determines that it has no data to send (step S11: NO), that is, if it determines that it does not need to send the first data 41, it terminates this series of processes.

[0041] On the other hand, in the process of step S11, if the processing unit 11 determines that it has data to send (step S11: YES), that is, if it determines that it needs to send the first data 41, it proceeds to step S12. In the process of step S12, the processing unit 11 sends the first data 41. Having sent the first data 41, the processing unit 11 terminates this series of processes.

[0042] The processing unit 21 of the second communication device 20 performs the same processing as the processing unit 11 of the first communication device 10. As shown in Figure 4, once this series of processes begins, in step S11, the processing unit 21 determines whether or not it has data to transmit. In other words, the processing unit 21 determines whether or not the second communication device 20 needs to transmit the second data 42.

[0043] In the process of step S11, if the processing unit 21 determines that it has no data to send (step S21: NO), that is, if it determines that it does not need to send the second data 42, it terminates this series of processes.

[0044] On the other hand, in the process of step S11, if the processing unit 21 determines that it has data to send (step S11: YES), that is, if it determines that it needs to send the second data 42, it proceeds to step S12. In the process of step S12, the processing unit 21 sends the second data 42. Having sent the second data 42, the processing unit 21 terminates this series of processes.

[0045] The processing unit 51 of the management device 50 also performs the same processing as the processing unit 11 of the first communication device 10. As shown in Figure 4, once this series of processes begins, in step S11, the processing unit 51 determines whether or not it has data to transmit. In other words, the processing unit 51 determines whether or not the management device 50 needs to transmit the third data 43.

[0046] In the process of step S11, if the processing unit 51 determines that it has no data to send (step S11: NO), that is, if it determines that it does not need to send the third data 43, it terminates this series of processes.

[0047] On the other hand, in the process of step S11, if the processing unit 51 determines that it has data to send (step S11: YES), that is, if it determines that it needs to send the third data 43, it proceeds to step S12. In the process of step S12, the processing unit 51 sends the third data 43. Having sent the third data 43, the processing unit 51 terminates this series of processes.

[0048] <Overview of the second communication method> As explained above, in the communication network system 100, each communication device communicates with each other by transmitting data using the first communication method. In the first communication method, the order in which each communication device transmits data is predetermined. Each communication device then transmits data in the predetermined order in response to a start signal 40 transmitted by the management device 50.

[0049] In this type of communication method, because the transmission timing of the start signal 40 is periodic and the transmission order of the communication devices is fixed, the timing of data transmission by each communication device may be somewhat periodic. Therefore, in the first communication method, if external noise occurs periodically, the timing of data transmission by a particular communication device may coincide with the timing of noise occurrence. In that case, a communication error occurs in which the communication device cannot transmit data as long as the data transmission timing and the noise occurrence timing coincide.

[0050] In addition to the above-mentioned aspects, in the first communication method, for example, the occurrence of noise may prevent the message from being received properly. Also, in the first communication method, for example, the occurrence of noise may limit the data transmission time, making it impossible to transmit all the data that should be sent. Thus, in the first communication method, the occurrence of noise can lead to various types of communication errors.

[0051] When a communication error occurs due to noise in the communication network system 100, the communication device switches the communication method from the first communication method to the second communication method. Figure 5 shows an example of how data is transmitted to the communication bus 30 in the second communication method. The rectangles in Figure 5, as in Figure 2, represent the data transmitted by each communication device. And, as in Figure 2, the area of ​​the rectangles in Figure 5 is represented as being larger in proportion to the data capacity. Therefore, in Figure 2, the second data 42 has the largest capacity. Note that each communication device does not transmit the same amount of data every time. Therefore, although the second data 42 is represented as having the largest capacity in Figure 2, it is not necessarily the case that the second data 42 has the largest capacity at other times.

[0052] In Figure 5, as in Figure 2, the data is transmitted sequentially from left to right. In the example shown in Figure 5, first, the second communication device 20 transmits the second data 42. Next, the management device 50 transmits the third data 43. Then, the first communication device 10 transmits the first data 41.

[0053] As shown in the example in Figure 5, in the second communication method, unlike the first communication method, the start signal 40 is not transmitted. Therefore, in the second communication method, each communication device transmits data at any time without waiting for the start signal 40 to be transmitted by the management device 50.

[0054] Furthermore, in the example shown in Figure 2, the data is transmitted in the order of first data 41, second data 42, and third data 43. On the other hand, in the example shown in Figure 5, the data is transmitted in the order of second data 42, third data 43, and first data 41. As described above, in the second communication method, the communication device transmits data at any time. In other words, unlike the first communication method, the order in which data is transmitted is not fixed in the second communication method. Therefore, the order in which the communication device transmits data in the second communication method is not limited to the order shown in Figure 5.

[0055] In the second communication method, the order in which communication devices transmit data is not fixed, so there is a possibility that multiple communication devices may transmit data at the same time. In this case, the data will collide, and communication devices will not be able to transmit data to other communication devices. Therefore, in the second communication method, communication devices transmit data only after confirming that other communication devices are not transmitting data.

[0056] Furthermore, even if a communication device confirms that no other communication devices are transmitting data, if multiple communication devices start transmitting data simultaneously, the data will collide. In this case, the communication device detects the data collision. The communication device then retransmits the data it was unable to send after confirming that no other communication devices are transmitting data and waiting a certain amount of time. By repeating this retransmission process, the communication device is eventually able to transmit the data.

[0057] Thus, in the second communication method, each communication device in the communication network system 100 transmits data regardless of a predetermined order, only when no other communication device is transmitting data.

[0058] Figure 6 shows the communication between the first communication device 10, the second communication device 20, and the management device 50 in the second communication method. As mentioned above, in the second communication method, the order in which each communication device transmits data is not fixed. Figure 6 shows the communication when each communication device transmits data in the order shown in Figure 5.

[0059] In the example shown in Figure 6, the second communication device 20 first transmits the second data 42 to the first communication device 10 and the management device 50. At this time, the second communication device 20 transmits the second data 42 only after confirming that the management device 50 and the first communication device 10 have not transmitted any data.

[0060] In the example shown in Figure 6, the management device 50 then transmits the third data 43 to the first communication device 10 and the second communication device 20. At this time, the management device 50 transmits the third data 43 only after confirming that the first communication device 10 and the second communication device 20 have not yet transmitted any data.

[0061] In the example shown in Figure 6, the first communication device 10 then transmits the first data 41 to the second communication device 20 and the management device 50. At this time, the first communication device 10 transmits the first data 41 only after confirming that the management device 50 and the second communication device 20 have not yet transmitted any data.

[0062] <Processing performed by the processing unit of each communication device in the second communication method> Figure 7 shows a series of processes performed by each communication device in the communication network system 100 when transmitting data in the second communication method. In other words, the first communication device 10, the second communication device 20, and the management device 50 each perform the processes shown in Figure 7 when transmitting data.

[0063] This series of processes is performed by the processing units of each communication device in the communication network system 100. Specifically, this series of processes is performed by the processing unit 11 of the first communication device 10, the processing unit 21 of the second communication device 20, and the processing unit 51 of the management device 50.

[0064] First, we will explain the flow of the processing unit 11 of the first communication device 10 when it performs the series of processes shown in Figure 7. As shown in Figure 7, once this series of processes is started, in step S21, the processing unit 11 determines whether or not there is a communication device transmitting data in the communication network system 100. At this time, the processing unit 11 determines that there is a communication device transmitting data if the first communication device 10 has received the third data 43 transmitted by the management device 50 or the second data 42 transmitted by the second communication device 20.

[0065] In the process of step S21, if the processing unit 11 determines that there is a communication device transmitting data (step S21: YES), it repeats the process of step S21. On the other hand, in the process of step S21, if the processing unit 11 determines that there is no communication device transmitting data (step S21: NO), it proceeds to step S22. In the process of step S22, the processing unit 11 transmits data. Since the data transmitted by the first communication device 10 is the first data 41, the processing unit 11 transmits the first data 41 in the process of step S22.

[0066] In the next step, S23, the processing unit 11 determines whether the transmitted data has collided with other data. If a communication device in the communication network system 100 detects a data collision, the communication device in the communication network system 100 that detected the collision transmits a jam signal. A jam signal is a signal that notifies that a data collision has occurred. Based on whether or not it has received a jam signal, the processing unit 11 determines whether or not the transmitted data has collided with other data.

[0067] In step S23, if the processing unit 11 determines that the transmitted data has collided with other data (step S23: YES), it proceeds to step S24. In step S24, the processing unit 11 retransmits the first data 41. At this time, if the processing unit 11 retransmits the first data 41 immediately after a data collision occurs, there is a possibility that it will collide with the already collided data again. Therefore, the processing unit 11 waits for a while before transmitting the first data 41. The communication device that transmitted the data that collided with the first data 41 also waits for a while before retransmitting the data, similar to the processing unit 11. Therefore, if the time that the processing unit 11 waits and the time that the communication device waits are different, the processing unit 11 and the communication device can transmit the data without causing another collision. After retransmitting the first data 41, the processing unit 11 executes the process in step S23 again.

[0068] In step S23, if the processing unit 11 determines that the transmitted data does not collide with other data (step S23: NO), it terminates the series of processes shown in Figure 7.

[0069] The processing unit 21 of the second communication device 20 also performs the same series of processes as shown in Figure 7, as the processing unit 11. As shown in Figure 7, when this series of processes is started, in step S21, the processing unit 21 determines whether or not there is a communication device transmitting data in the communication network system 100. At this time, the processing unit 21 determines that there is a communication device transmitting data if the second communication device 20 has received the third data 43 transmitted by the management device 50 or the first data 41 transmitted by the first communication device 10.

[0070] In the process of step S21, if the processing unit 21 determines that there is a communication device transmitting data (step S21: YES), it repeats the process of step S21. On the other hand, in the process of step S21, if the processing unit 21 determines that there is no communication device transmitting data (step S21: NO), it proceeds to step S22. In the process of step S22, the processing unit 21 transmits data. Since the data transmitted by the second communication device 20 is the second data 42, the processing unit 21 transmits the second data 42 in the process of step S22.

[0071] In the next step, S23, the processing unit 21 determines whether the transmitted data has collided with other data. The processing unit 21 determines whether the transmitted data has collided with other data based on whether or not it has received a jam signal.

[0072] In step S23, if the processing unit 21 determines that the transmitted data has collided with other data (step S23: YES), it proceeds to step S24. In step S24, the processing unit 21 retransmits the second data 42. At this time, the processing unit 21 transmits the second data 42 after a delay. After retransmitting the second data 42, the processing unit 21 executes the process of step S23 again.

[0073] In step S23, if the processing unit 21 determines that the transmitted data does not collide with other data (step S23: NO), it terminates the series of processes shown in Figure 7.

[0074] The processing unit 51 of the control device 50 also performs the same series of processes as the processing unit 11, as shown in Figure 7. As shown in Figure 7, when this series of processes is started, in step S21, the processing unit 51 determines whether or not there is a communication device transmitting data in the communication network system 100. At this time, the processing unit 51 determines that there is a communication device transmitting data if the management device 50 has received the first data 41 transmitted by the first communication device 10 or the second data 42 transmitted by the second communication device 20.

[0075] In the process of step S21, if the processing unit 51 determines that there is a communication device transmitting data (step S21: YES), it repeats the process of step S21. On the other hand, in the process of step S21, if the processing unit 51 determines that there is no communication device transmitting data (step S21: NO), it proceeds to step S22. In the process of step S22, the processing unit 51 transmits data. Since the data transmitted by the management device 50 is the third data 43, the processing unit 51 transmits the third data 43 in the process of step S22.

[0076] In the next step, S23, the processing unit 51 determines whether the transmitted data has collided with other data. The processing unit 51 determines whether the transmitted data has collided with other data based on whether or not it has received a jam signal.

[0077] In step S23, if the processing unit 51 determines that the transmitted data has collided with other data (step S23: YES), it proceeds to step S24. In step S24, the processing unit 51 retransmits the second data 42. At this time, the processing unit 51 transmits the third data 43 after a delay. After retransmitting the third data 43, the processing unit 21 executes the process of step S23 again.

[0078] In step S23, if the processing unit 51 determines that the transmitted data does not conflict with other data (step S23: NO), it terminates the series of processes shown in Figure 7.

[0079] <Data transmission and reception when a communication device switches communication methods> As described above, the communication network system 100 switches to the second communication method if communication errors frequently occur with a specific communication device in the first communication method. Figure 8 shows a specific example of communication between the first communication device 10, the second communication device 20, and the management device 50 during such a communication method switch.

[0080] The communication shown in Figure 8 is executed when two conditions are met. The first condition is that the number of communication errors that occur while any communication device in the communication network system 100 transmits data a predetermined number of times is equal to or greater than a default value. The default value will be described later.

[0081] The second condition is that the communication devices in the communication network system 100 are capable of switching to the second communication method. The state in which a communication device is capable of switching to the second communication method means that switching the communication method by switching the communication device to the second communication method does not disrupt the operation of the vehicle. As mentioned above, in the second communication method, data cannot be transmitted when other communication devices are transmitting data. In other words, in the second communication method, the opportunity for each communication device to transmit data is not guaranteed. Therefore, depending on the vehicle's situation, switching the communication method of the communication devices in the communication network system 100 may cause a particular communication device to be unable to transmit data for a long period of time. Depending on the vehicle's situation, the communication network system 100 may not switch the communication method of the communication devices to the second communication method in order to prioritize securing the opportunity to transmit data.

[0082] When these two conditions are met, the first communication device 10 transmits a jamming signal, as shown in the upper part of Figure 8. The jamming signal is a signal that interferes with the detection of the start signal 40 by each communication device in the communication network system 100. Thus, in this example, the first communication device 10 is a jamming device that transmits a jamming signal depending on the status of the communication error.

[0083] The first communication device 10 transmits an interference signal at the same time that the management device 50 transmits the start signal 40. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0084] As shown in the middle section of Figure 8, the first communication device 10, the second communication device 20, and the management device 50 switch to the second communication method if they do not detect the start signal 40 for a predetermined period of time. In this way, each communication device in the communication network system 100 switches its communication method to the second communication method.

[0085] As shown in the middle section of Figure 8, the first communication device 10, the second communication device 20, and the management device 50 communicate with each other using the second communication method after switching to the second communication method. In other words, the first communication device 10, the second communication device 20, and the management device 50 communicate with each other in the manner illustrated in Figure 6.

[0086] As shown in the lower part of Figure 8, the management device 50 transmits a start signal 40 if no data is transmitted for a certain period of time after switching to the second communication method. The first communication device 10 and the second communication device 20, upon receiving the start signal 40, switch back to the first communication method. The management device 50, which transmitted the start signal 40, also switches back to the first communication method. In this way, each communication device in the communication network system 100 returns to the first communication method.

[0087] <Status of communication errors acquired by the first communication device 10> In the specific example shown in Figure 8, as described above, the first communication device 10 transmits a jamming signal depending on the status of the communication error. The first communication device 10 acquires the status of the communication error in the communication network system 100 in order to transmit a jamming signal as needed.

[0088] Figure 9 is a table showing the status of communication errors in the communication network system 100, acquired by the first communication device 10. As shown in Figure 9, the first communication device 10 acquires information on the number of communication errors that occurred while each communication device transmitted data a predetermined number of times. In other words, the first communication device 10 acquires information on the number of communication errors that occurred for each communication device while the first communication device 10 itself, the second communication device 20, and the management device 50 transmitted data a predetermined number of times. In Figure 9, the number of communication errors for each communication device acquired by the first communication device 10 is represented by symbols such as "A1", "A2", and "A3".

[0089] As shown in Figure 9, a default value is set for each communication device. The default value is a threshold used by the first communication device 10 to determine whether or not to switch the communication method used by the communication device from the first communication method to the second communication method, based on the number of communication errors in the communication device. The first communication device 10 transmits an interference signal if the number of communication errors for any communication device exceeds the default value. In Figure 9, the default values ​​set for each communication device are represented by symbols such as "B1", "B2", and "B3".

[0090] <Processing when the first communication device 10 transmits an interference signal> Figure 10 shows a series of processes performed by the first communication device 10 when transmitting an interference signal. This series of processes is performed by the processing unit 11 of the first communication device 10, which processes according to a program stored in the storage device 12.

[0091] This series of processes is executed when the first communication device 10 obtains information on the number of communication errors that occurred during the transmission of data a predetermined number of times to either the first communication device 10 itself, the second communication device 20, or the management device 50.

[0092] As shown in Figure 10, when this series of processes is started, in step S101, the processing unit 11 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value.

[0093] In the process of step S101, if the processing unit 11 determines that the number of communication errors is not equal to or greater than a default value (step S101: NO), that is, if it determines that the number of communication errors is less than a default value, it terminates this series of processes.

[0094] In the process of step S101, if the processing unit 11 determines that the number of communication errors is equal to or greater than a predetermined value (step S101: YES), it proceeds to step S102.

[0095] In step S102, the processing unit 11 grasps the status of the vehicle. The processing unit 11 grasps the status of the vehicle based on data transmitted by the communication device in the communication network system 100. For example, if the vehicle is in autonomous driving mode, the communication device in the communication network system 100 that communicates during autonomous driving to realize the autonomous driving function transmits data indicating that the vehicle is in autonomous driving mode.

[0096] In the next step, S103, the processing unit 11 determines whether the communication device in the communication network system 100 is capable of switching to the second communication method. In the process of step S103, the processing unit 11 determines whether the communication device is capable of switching to the second communication method based on the vehicle status obtained in the process of step S102.

[0097] The processing unit 11 determines that the communication device cannot switch to the second communication method if the vehicle's status requires prioritizing the securing of data transmission opportunities. For example, the processing unit 11 determines that the communication device cannot switch to the second communication method if the vehicle is in automatic driving mode. Also, for example, the processing unit 11 determines that the communication device cannot switch to the second communication method if the vehicle is undergoing fault diagnosis.

[0098] In step S103, if the processing unit 11 determines that the communication device is not capable of switching to the second communication method (step S103: NO), it terminates this series of processes. In step S103, if the processing unit 11 determines that the communication device can switch to the second communication method (step S103: YES), it proceeds to step S104. In step S104, the processing unit 11 transmits a jamming signal. This process corresponds to the process performed by the first communication device 10 in the upper part of Figure 8. In this way, the processing unit 11 transmits a jamming signal based on the acquired communication error status and the vehicle status it has grasped.

[0099] The processing unit 11 that transmitted the interference signal terminates this series of processes. <Process for the communication device to switch to the second communication method> Figure 11 shows a series of steps when each communication device in the communication network system 100 switches the communication method from the first communication method to the second communication method. This series of processes is executed by the processing unit 11 of the first communication device 10, the processing unit 21 of the second communication device 20, and the processing unit 51 of the management device 50. This process corresponds to the process executed by the first communication device 10, the second communication device 20, and the management device 50 shown in the middle section of Figure 8.

[0100] First, let's explain the flow of the processing unit 11 of the first communication device 10 when it performs the series of processes shown in Figure 11. The processing unit 11 performs the series of processes shown in Figure 11 when it does not detect the start signal 40 for a predetermined time.

[0101] As shown in Figure 11, when this series of processes is started, in the process of step S31, the processing unit 11 switches to the second communication method. At this time, the processing unit 11 switches the flag that determines the communication method in the first communication device 10 from the flag for the first communication method to the flag for the second communication method. As a result, the communication method in the first communication device 10 switches from the first communication method to the second communication method. In this way, the first communication device 10 switches its communication method from the first communication method to the second communication method.

[0102] In the next step S32, the processing unit 11 determines whether or not there is data to be transmitted. At this time, the processing unit 11 determines whether or not there is data to be transmitted based on whether or not the first communication device 10 needs to transmit the first data 41.

[0103] In step S32, if the processing unit 11 determines that there is no data to transmit (step S32: NO), it terminates this series of processes. In step S32, if the processing unit 11 determines that there is data to transmit (step S32: YES), it proceeds to step S33. In step S33, the processing unit 11 performs offset time setting processing.

[0104] The offset time setting process is the process of setting an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data, when there is data to be transmitted immediately after switching to the second communication method. In the second communication method, the order in which each communication device transmits data is not set. Each communication device sets an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data, thereby suppressing data collisions immediately after the communication device switches to the second communication method.

[0105] When setting the offset time, the processing unit 11 sets a shorter offset time, for example, the larger the capacity of the first data 41 to be transmitted. This allows the processing unit 11 to preferentially transmit the first data 41 with a large capacity in the second communication method.

[0106] When setting the offset time, the processing unit 11 sets a shorter offset time for devices with higher priority, such as the first communication device 10. In this case, each communication device in the communication network system 100 has a predetermined priority. By setting a shorter offset time for devices with higher priority, the processing unit 11 enables communication devices with higher priority to transmit data preferentially within the communication network system 100.

[0107] In the next step, S34, the processing unit 11 transmits the data taking the offset time into consideration. At this time, the processing unit 11 starts transmitting the first data 41 after the offset time set in step S33 has elapsed.

[0108] The processing unit 11 that transmitted the first data 41 terminates this series of processes. The processing unit 21 of the second communication device 20 also performs the same series of processes as shown in Figure 11, as with the processing unit 11. The processing unit 21 performs the series of processes shown in Figure 11 when it does not detect the start signal 40 for a predetermined period of time.

[0109] As shown in Figure 11, when this series of processes is initiated, in step S31, the processing unit 21 switches to the second communication method. At this time, the processing unit 21 switches the flag that determines the communication method of the second communication device 20 from the flag for the first communication method to the flag for the second communication method. As a result, the communication method in the second communication device 20 switches from the first communication method to the second communication method. In this way, the second communication device 20 switches its communication method from the first communication method to the second communication method.

[0110] In the next step S32, the processing unit 21 determines whether or not there is data to be transmitted. At this time, the processing unit 21 determines whether or not there is data to be transmitted based on whether or not the second communication device 20 needs to transmit the second data 42.

[0111] In step S32, if the processing unit 21 determines that there is no data to transmit (step S32: NO), it terminates this series of processes. In step S32, if the processing unit 21 determines that there is data to transmit (step S32: YES), it proceeds to step S33. In step S33, the processing unit 21 performs offset time setting processing.

[0112] In the next step, S34, the processing unit 21 transmits the data taking the offset time into consideration. At this time, the processing unit 21 starts transmitting the second data 42 after the offset time set in step S33 has elapsed.

[0113] The processing unit 21, which transmitted the second data 42, terminates this series of processes. The processing unit 51 of the control device 50 also performs the same series of processes as shown in Figure 11, as with the processing unit 11. The processing unit 51 performs the series of processes shown in Figure 11 when it does not detect the start signal 40 for a predetermined period of time.

[0114] As shown in Figure 11, when this series of processes is initiated, in step S31, the processing unit 51 switches to the second communication method. At this time, the processing unit 51 switches the flag that determines the communication method of the management device 50 from the flag for the first communication method to the flag for the second communication method. As a result, the communication method in the management device 50 switches from the first communication method to the second communication method. In this way, the management device 50 switches its communication method from the first communication method to the second communication method.

[0115] In the next step S32, the processing unit 51 determines whether or not there is data to be transmitted. At this time, the processing unit 51 determines whether or not there is data to be transmitted based on whether or not the management device 50 needs to transmit the third data 43.

[0116] In step S32, if the processing unit 51 determines that there is no data to transmit (step S32: NO), it terminates this series of processes. In step S32, if the processing unit 51 determines that there is data to transmit (step S32: YES), it proceeds to step S33. In step S33, the processing unit 51 performs offset time setting processing.

[0117] In the next step, S34, the processing unit 51 transmits the data taking the offset time into consideration. At this time, the processing unit 51 starts transmitting the third data 43 after the offset time set in step S33 has elapsed.

[0118] The processing unit 51 that transmitted the third data 43 terminates this series of processes. <Processing when the management device 50 switches the communication method to the first communication method> Figure 12 shows the sequence of processes when the management device 50 switches the communication method of the communication device to the first communication method. This sequence of processes is executed by the processing unit 51 of the management device 50. The processing unit 51 executes this sequence of processes after the communication method has been switched to the second communication method in step S31 of Figure 11. This process corresponds to the process executed by the management device 50 shown in the lower part of Figure 8.

[0119] As shown in Figure 12, once this series of processes is started, in step S41, the processing unit 51 determines whether a state in which no data is transmitted has continued for a certain period of time. In other words, the processing unit 51 determines whether a state in which the first communication device 10, the second communication device 20, and the management device 50 have not transmitted data using the second communication method has continued for a certain period of time.

[0120] In the process of step S41, if the processing unit 51 determines that the state in which no data is transmitted has not continued for a certain period of time (step S41: NO), it repeats the process of step S41.

[0121] In step S41, if the processing unit 51 determines that no data has been transmitted for a certain period of time (step S41: YES), it proceeds to step S42. In step S42, the processing unit 51 transmits a start signal 40.

[0122] In the next step, S43, the processing unit 51 switches the communication method of the management device 50 to the first communication method. At this time, the processing unit 51 switches the flag that determines the communication method of the management device 50 from the flag for the second communication method to the flag for the first communication method. As a result, the communication method of the management device 50 switches from the second communication method to the first communication method. In this way, the management device 50 returns its communication method from the second communication method to the first communication method.

[0123] The processing unit 51, which has switched the communication method to the first communication method, terminates this series of processes. Furthermore, as shown in the lower part of Figure 8, when the processing unit 51 transmits the start signal 40 in step S42, the first communication device 10 and the second communication device 20, having received the start signal 40, switch the flag that determines the communication method from the flag for the second communication method to the flag for the first communication method. As a result, the communication method of the first communication device 10 and the second communication device 20 transitions from the second communication method to the first communication method. In this way, the first communication device 10 and the second communication device 20 return their communication method from the second communication method to the first communication method.

[0124] <Operation of this embodiment> In the communication network system 100 and the vehicle equipped with the communication network system 100, the jamming device transmits a jamming signal according to the status of the communication error. As a result, the detection of the start signal 40 by the communication device is disrupted in the communication network system 100 and the vehicle equipped with the communication network system 100. Then, in the communication network system 100 and the vehicle equipped with the communication network system 100, the communication method of each communication device switches from the first communication method to the second communication method.

[0125] <Effects of this embodiment> (1) In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order. Therefore, the communication network system 100 and the vehicle equipped with the communication network system 100 can suppress communication errors that occur in specific communication devices.

[0126] (2) The jamming device acquires the status of communication errors in the communication network system 100. The jamming device then transmits a jamming signal based on the acquired status of communication errors. In the communication network system 100, the jamming device transmits a jamming signal based on the status of communication errors it has acquired. This allows the communication network system 100 to switch the communication method of each communication device to the second communication method in response to the status of communication errors.

[0127] (3) The communication network system 100 is installed in the vehicle. The jamming device grasps the status of the vehicle. The jamming device then transmits a jamming signal based on the acquired communication error status and the vehicle status it has grasped.

[0128] In the second communication method, data can be transmitted regardless of the predetermined order. However, data cannot be transmitted when other communication devices are transmitting data. In other words, in the second communication method, each communication device is not guaranteed the opportunity to transmit data. Therefore, depending on the vehicle's condition, switching the communication method of each communication device in the communication network system 100 may cause a particular communication device to be unable to transmit data for an extended period of time.

[0129] In the communication network system 100, the jamming device decides whether or not to transmit a jamming signal depending on the vehicle's condition. This allows the communication network system 100 to prioritize ensuring opportunities for data transmission by refraining from transmitting jamming signals depending on the vehicle's condition.

[0130] (4) The jamming device acquires information on the number of communication errors that occurred while each communication device transmitted data a predetermined number of times, as a status of communication errors. In the communication network system 100, the jamming device acquires information on the frequency of communication errors in each communication device as a status of communication errors. As a result, the communication network system 100 can switch the communication method of each communication device to the second communication method according to the frequency of communication errors in each communication device.

[0131] (5) The jamming device transmits a jamming signal when the number of communication errors obtained as a status of communication errors exceeds a predetermined value. In the communication network system 100, the jamming device transmits a jamming signal when the number of communication errors exceeds a predetermined value. This allows the communication network system 100 to switch the communication method to the second communication method when the frequency of communication errors exceeds a predetermined frequency.

[0132] (6) In the communication network system 100, default values ​​are set for each communication device. The jamming device transmits a jamming signal when the number of communication errors for any communication device exceeds a default value.

[0133] In the above-described communication network system 100, the jamming device transmits a jamming signal if the number of communication errors of any communication device exceeds a corresponding default value. This allows the communication network system 100 to switch communication methods while closely monitoring the communication error status of each communication device.

[0134] (7) The jamming device does not transmit a jamming signal if it detects that the vehicle is in autonomous driving mode. When the vehicle is in autonomous driving mode, it is desirable that each communication device communicates using the first communication method, which guarantees an opportunity to transmit data. In the communication network system 100, the jamming device does not transmit a jamming signal when the vehicle is in autonomous driving mode. In other words, the communication network system 100 does not switch to the second communication method when the vehicle is in autonomous driving mode. This ensures that each communication device has an opportunity to communicate. That is, the communication network system 100 can prevent the execution of autonomous driving by the vehicle from being hindered by switching to the second communication method.

[0135] (8) The jamming device does not transmit a jamming signal if it detects that the vehicle is undergoing fault diagnosis. When a vehicle is undergoing fault diagnosis, it is desirable that each communication device communicates using the first communication method, which guarantees an opportunity to transmit data. In the communication network system 100, the jamming device does not transmit a jamming signal when a vehicle is undergoing fault diagnosis. In other words, the communication network system 100 does not switch the communication method to the second communication method when a vehicle is undergoing fault diagnosis. This ensures that each communication device has an opportunity to communicate. That is, the communication network system 100 can prevent the execution of fault diagnosis by the vehicle from being hindered by switching the communication method to the second communication method.

[0136] (9) The jamming device is applied to a communication network system 100 comprising a plurality of communication devices and a management device 50 that transmits a start signal 40 to the communication devices. The plurality of communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal 40. Furthermore, if the plurality of communication devices do not sense the start signal 40 for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order. The jamming device transmits a jamming signal that interferes with the sensing of the start signal 40 by the communication devices, depending on the communication error situation in the communication network system 100.

[0137] The jamming device transmits a jamming signal depending on the status of the communication error. As a result, in the above-mentioned communication network system 100, the detection of the start signal 40 by the communication device is disrupted, and the communication method switches from the first communication method to the second communication method.

[0138] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0139] This allows the jamming device to suppress communication errors that occur in specific communication devices. (10) When the communication device switches from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, it sets an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data. The communication device then starts transmitting the data when the set offset time has elapsed.

[0140] In the second communication method, unlike the first method, the order in which each communication device transmits data is not predetermined. Therefore, immediately after switching to the second communication method, data collisions can occur because multiple communication devices may start transmitting data simultaneously.

[0141] In the communication network system 100, communication devices that have switched to the second communication method begin transmitting data only after a set offset time has elapsed. This allows the communication network system 100 to suppress data collisions immediately after switching to the second communication method.

[0142] (11) When the communication device switches from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, it sets an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data. At this time, the communication device sets the offset time so that it becomes shorter the larger the capacity of the data to be transmitted. The communication device then starts transmitting the data when the set offset time has elapsed.

[0143] In the communication network system 100, a communication device that has switched to the second communication method will begin transmitting data only after an offset time, which is set based on the capacity of the data it intends to transmit, has elapsed. This allows the communication network system 100 to prioritize the transmission of larger data while suppressing data collisions when a communication device switches to the second communication method.

[0144] (12) Each communication device has a predetermined priority. When a communication device switches from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, it sets an offset time from the moment the communication method is switched to the second communication method until it starts transmitting the data. At this time, the communication device sets the offset time so that it becomes shorter for higher priority devices. The communication device starts transmitting the data when the set offset time has elapsed.

[0145] In the communication network system 100, a communication device that has switched to the second communication method will begin transmitting data only after a predetermined offset time has elapsed, based on a set priority order. This allows the communication network system 100 to prioritize data transmission by higher-priority communication devices while suppressing data collisions when a communication device switches to the second communication method.

[0146] (13) The program is applied to a jamming device of the communication network system 100. The communication network system 100 comprises a plurality of communication devices and a management device 50 that transmits a start signal 40. The plurality of communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after sensing the start signal 40. Furthermore, if the plurality of communication devices do not sense the start signal 40 for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order. The program causes the jamming device to transmit a jamming signal that interferes with the sensing of the start signal 40 by the communication devices, based on the communication error situation in the communication network system 100.

[0147] The program causes the jamming device to send a jamming signal depending on the communication error situation. As a result, in the above-mentioned communication network system 100, the detection of the start signal 40 by the communication device is disrupted, and the communication method switches from the first communication method to the second communication method.

[0148] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0149] This allows the program to suppress communication errors that occur in specific communication devices. In the above embodiment, the program is stored in the storage device 12 of the first communication device 10. The program may also be provided in a state recorded on a recording medium. Examples of recording media on which the program is recorded include memory such as USB memory, SSD, and SD card, as well as CD-ROMs and optical discs.

[0150] (14) The communication network system 100 is composed of a plurality of communication devices. The communication network system 100 includes a management device 50 that transmits a start signal 40, and a jamming device that transmits a jamming signal that interferes with the detection of the start signal 40 by the communication devices. In the communication network system 100, the plurality of communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after detecting the start signal 40. The communication method is the communication method in such a communication network system 100. The communication method includes a step (step S104) in which the jamming device transmits a jamming signal based on the status of a communication error in the communication network system 100. The communication method includes a step (step S31) in which, if the plurality of communication devices continue to not detect the start signal 40 for a predetermined time, they switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of a predetermined order.

[0151] In the communication network system 100, the communication method involves causing a jamming device to send a jamming signal depending on the status of the communication error. As a result, in the above-mentioned communication network system 100, the detection of the start signal 40 by the communication device is disrupted, and the communication method switches from the first communication method to the second communication method.

[0152] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0153] This allows the communication method to suppress communication errors that occur in specific communication devices. <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0154] In this embodiment, the management device 50 transmits the third data 43. The management device 50 does not need to also function as a communication device that transmits data. In other words, the management device 50 only needs to be a device that transmits the start signal 40, and does not need to also function as a communication device that transmits the third data 43 in the first communication method using the start signal 40 as a signal. In this case, the management device 50 does not need to also function as a communication device that transmits the third data 43 in the second communication method.

[0155] In this embodiment, the first communication device 10 transmits the first data 41. On the other hand, the jamming device does not need to also function as a communication device that transmits data. In other words, the first communication device 10, which functions as a jamming device in this embodiment, only needs to be a device that transmits a jamming signal, and does not need to also function as a communication device that transmits the first data 41 in the first communication method using the start signal 40 as a signal. In this case, the first communication device 10 does not need to also function as a communication device that transmits the first data 41 in the second communication method.

[0156] In this embodiment, the communication devices in the communication network system 100 are connected via a wired connection through the communication bus 30. Alternatively, the communication devices in the communication network system 100 may be connected wirelessly.

[0157] In this embodiment, the first communication device 10 acquires the communication error status for all communication devices in the communication network system 100. Alternatively, the first communication device 10 may acquire the communication error status for only specific communication devices.

[0158] In this embodiment, the default value is set for each communication device. On the other hand, in the communication network system 100, the default value may be common to multiple communication devices. In the communication network system 100, the default value may be common to all communication devices.

[0159] In this embodiment, the first communication device 10 acquires the communication error status for each communication device in the communication network system 100. Alternatively, the first communication device 10 may acquire the communication error status for the entire communication network system 100.

[0160] In this case, the jamming device acquires information as a status of communication errors, specifically the number of communication errors that occurred in the communication network system 100 during a predetermined number of data transmissions. In the communication network system 100, the jamming device also acquires information as a status of communication errors, specifically the frequency of communication errors occurring throughout the entire communication network system 100. This allows the communication network system 100 to switch the communication method of the communication device to the second communication method according to the frequency of communication errors occurring in the data transmitted in the communication network system 100.

[0161] In this case, a single default value is set for the entire communication network system 100, rather than for each individual communication device. In this embodiment, the first communication device 10 transmits an interference signal based on the communication error status it has acquired. Alternatively, the first communication device 10 may transmit an interference signal based on a request from another communication device that has acquired the communication error status, rather than acquiring the communication error status itself.

[0162] Figure 13 shows a specific example of communication when the first communication device 10, the second communication device 20, and the management device 50 in the first modified communication network system 100 switch the communication method to the second communication method. The first communication device 10, the second communication device 20, and the management device 50 in the first modified communication network system 100 perform the communication shown in Figure 13 instead of the communication shown in Figure 8.

[0163] The communication shown in Figure 13 is executed when the same two conditions as in Figure 8 are met. When both conditions are met, as shown in the upper part of Figure 13, the second communication device 20 transmits a jamming request signal to the first communication device 10, which is a jamming device. A jamming request signal is a signal that requests the jamming device to transmit a jamming signal. Thus, in this example, in the first modified example, the second communication device 20 is a jamming request device that transmits a jamming request signal depending on the status of the communication error.

[0164] As shown in the upper part of Figure 13, the first communication device 10 transmits an interference signal at the same time that the management device 50 transmits the start signal 40, after receiving the interference request signal. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0165] The communication pattern after the first communication device 10 transmits an interference signal is the same as in Figure 8. In the first modified example, the second communication device 20 acquires the status of communication errors in the communication network system 100 in order to transmit an interference request signal as needed. At this time, the second communication device 20 acquires information as the status of communication errors, specifically the number of communication errors that occurred while each communication device transmitted data a predetermined number of times, similar to the first communication device 10 in the above embodiment. Also, in the first modified example, a default value is set for each communication device, similar to the above embodiment.

[0166] Figure 14 shows a series of processes performed by the second communication device 20 when it transmits an interference request signal. This series of processes is performed by the processing unit 21 of the second communication device 20. This series of processes is performed when the second communication device 20 obtains information on the number of communication errors that occurred during the transmission of data a predetermined number of times to either the first communication device 10, the second communication device 20 itself, or the management device 50.

[0167] As shown in Figure 14, once this series of processes is initiated, in step S111, the processing unit 21 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value. This process is the same as the process executed by the processing unit 11 in step S101 in Figure 10.

[0168] In the process of step S111, if the processing unit 21 determines that the number of communication errors is not equal to or greater than a predetermined value (step S111: NO), it terminates this series of processes. In the process of step S111, if the processing unit 21 determines that the number of communication errors is equal to or greater than a predetermined value (step S111: YES), it proceeds to step S112.

[0169] In step S112, the processing unit 21 grasps the status of the vehicle. This process is the same as the process performed by the processing unit 11 in step S102 in Figure 10. In the next step, S113, the processing unit 21 determines whether the communication device in the communication network system 100 can switch to the second communication method. This process is the same as the process performed by the processing unit 11 in step S103 of Figure 10. Therefore, for example, the processing unit 21 determines that the communication device cannot switch to the second communication method if the vehicle is in automatic driving mode. Also, for example, the processing unit 21 determines that the communication device cannot switch to the second communication method if the vehicle is undergoing fault diagnosis.

[0170] In step S113, if the processing unit 21 determines that the communication device is not capable of switching to the second communication method (step S113: NO), it terminates this series of processes. In step S113, if the processing unit 21 determines that the communication device can switch to the second communication method (step S113: YES), it proceeds to step S114.

[0171] In step S114, the processing unit 21 transmits a jamming request signal. At this time, the processing unit 21 transmits the jamming request signal according to the first communication method. This process corresponds to the process performed by the second communication device 20 in the upper part of Figure 13. In this way, the processing unit 21 transmits the jamming request signal based on the acquired communication error status and the vehicle status it has grasped.

[0172] Upon receiving the interference request signal, the first communication device 10 transmits an interference signal in response to the interference request signal, instead of performing the series of processes shown in Figure 10. Thus, the communication network system 100 of the first modified example includes a jamming request device that transmits a jamming request signal requesting a jamming device to transmit a jamming signal. The jamming request device acquires the status of communication errors in the communication network system 100. Based on the acquired status of communication errors, the jamming request device transmits a jamming request signal. When the jamming device receives a jamming request signal, it transmits a jamming signal.

[0173] In the first modified communication network system 100, the jamming request device causes the jamming device to transmit a jamming signal according to the acquired communication error status. This allows the first modified communication network system 100 to switch the communication method of the communication device to the second communication method in response to the communication error status.

[0174] The first modified example of the communication network system 100 is installed in a vehicle. The jamming request device monitors the status of the vehicle. Based on the acquired communication error status and the monitored vehicle status, the jamming request device transmits a jamming request signal.

[0175] In the first modified example of the communication network system 100, the jamming request device decides whether or not to transmit a jamming request signal depending on the vehicle's status. This allows the communication network system to prioritize securing data transmission opportunities by refraining from transmitting a jamming request signal depending on the vehicle's status.

[0176] In the first modified example of the communication network system 100, the jamming request device acquires information as the status of communication errors, specifically the number of communication errors that occurred while the communication device transmitted data a predetermined number of times.

[0177] In the first modified communication network system 100, the jamming request device acquires information about the frequency of communication errors occurring in the communication device as a status of communication errors. As a result, the first modified communication network system 100 can switch the communication method of the communication device to the second communication method according to the frequency of communication errors occurring in the communication device.

[0178] In the first modified communication network system 100, the interference request device transmits an interference request signal when the number of communication errors obtained as a communication error status exceeds a predetermined value. In the first modified communication network system 100, the interference request device transmits an interference request signal when the number of communication errors exceeds a predetermined value. As a result, the first modified communication network system 100 can switch the communication method to the second communication method when the frequency of communication errors exceeds a predetermined frequency.

[0179] In the first modification example, default values ​​are set for each communication device. The jamming request device sends a jamming request signal when the number of communication errors for any communication device exceeds a default value.

[0180] In the first modified example of the communication network system 100, the jamming request device transmits a jamming request signal if the number of communication errors of any communication device exceeds a corresponding default value. This allows the first modified example of the communication network system 100 to switch to the second communication method while closely monitoring the communication error status of each communication device.

[0181] In the first modified communication network system 100, the interference request device does not transmit an interference request signal if the detected vehicle status indicates that the vehicle is in autonomous driving mode. In other words, the first modified communication network system 100 does not switch the communication method to the second communication method when the vehicle is in autonomous driving mode. This ensures that each communication device has an opportunity to communicate. That is, the first modified communication network system 100 can prevent the execution of autonomous driving by the vehicle from being hindered by switching the communication method to the second communication method.

[0182] In the first modified communication network system 100, the interference request device does not transmit an interference request signal if the detected vehicle status is undergoing fault diagnosis. In other words, the first modified communication network system 100 does not switch the communication method to the second communication method when a vehicle is undergoing fault diagnosis. This ensures that each communication device has an opportunity to communicate. That is, the first modified communication network system 100 can prevent the vehicle's fault diagnosis from being hindered by switching the communication method to the second communication method.

[0183] In the first example of modification, the second communication device 20 acquires the communication error status for all communication devices in the communication network system 100. On the other hand, the second communication device 20 may acquire the communication error status for only specific communication devices.

[0184] In the first modified example, the second communication device 20 acquires the communication error status for each communication device in the communication network system 100. Alternatively, the second communication device 20 may acquire the communication error status for the entire communication network system 100.

[0185] In this case, the jamming request device acquires information as a status of communication errors, specifically the number of communication errors that occurred in the communication network system 100 of the first modified example while data was being transmitted a predetermined number of times. In the communication network system 100 of the first modified example, the jamming request device acquires information as a status of communication errors, specifically the frequency of communication errors occurring throughout the entire communication network system 100. This allows the communication network system 100 of the first modified example to switch the communication method of the communication device to the second communication method according to the frequency of communication errors occurring in the data transmitted in the communication network system 100.

[0186] In the first modified example, the second communication device 20, which is a jamming request device, transmits a jamming request signal based on the acquired error status and the vehicle status it has grasped. Alternatively, the second communication device 20 may transmit a jamming request signal based only on the acquired error status without knowing the vehicle status. In this case, the first communication device 10, which is a jamming device that has received the jamming request signal, grasps the vehicle status and then transmits a jamming signal based on the vehicle status.

[0187] Figure 15 shows a specific example of communication when the first communication device 10, the second communication device 20, and the management device 50 in the second modified communication network system 100 switch the communication method to the second communication method. The first communication device 10, the second communication device 20, and the management device 50 in the second modified communication network system 100 perform the communication shown in Figure 15 instead of the communication shown in Figure 8.

[0188] In the communication shown in Figure 15, the second communication device 20 transmits an interference request signal to the first communication device 10 if the number of communication errors that occur while any communication device in the communication network system 100 transmits data a predetermined number of times exceeds a predetermined value.

[0189] Then, the first communication device 10, upon receiving the interference request signal, transmits an interference signal at the same time that the management device 50 transmits the start signal 40, provided that the communication device is capable of switching to the second communication method. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0190] The communication pattern after the first communication device 10 transmits an interference signal is the same as in Figure 8. Figure 16 shows a series of processes performed by the second communication device 20 when it transmits an interference request signal. This series of processes is performed by the processing unit 21 of the second communication device 20. This series of processes is performed when the second communication device 20 obtains information on the number of communication errors that occurred during the transmission of data a predetermined number of times to either the first communication device 10, the second communication device 20 itself, or the management device 50.

[0191] As shown in Figure 16, once this series of processes is initiated, in step S121, the processing unit 21 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value. This process is the same as the process executed by the processing unit 11 in step S101 in Figure 10.

[0192] In the process of step S121, if the processing unit 21 determines that the number of communication errors is not equal to or greater than a predetermined value (step S121: NO), it terminates this series of processes. In step S121, if the processing unit 21 determines that the number of communication errors is greater than or equal to a predetermined value (step S121: YES), it proceeds to step S122. In step S122, the processing unit 21 transmits a jamming request signal. At this time, the processing unit 21 transmits the jamming request signal according to the first communication method. This process corresponds to the process performed by the second communication device 20 in the upper part of Figure 15.

[0193] Figure 17 shows the sequence of processes when the first communication device 10 transmits an interference signal. This sequence of processes is executed by the processing unit 11 of the first communication device 10. The processing unit 11 transmits the interference signal by executing the sequence of processes shown in Figure 17 instead of the sequence of processes shown in Figure 10. This sequence of processes is executed when the first communication device 10 receives an interference request signal.

[0194] As shown in Figure 17, once this series of processes begins, in step S131, the processing unit 11 grasps the status of the vehicle. This process is the same as the process in step S102 in Figure 10.

[0195] In the next step, S132, the processing unit 11 determines whether the communication device in the communication network system 100 is capable of switching to the second communication method. This process is the same as the process in step S103 in Figure 10.

[0196] In step S132, if the processing unit 11 determines that the communication device is not capable of switching to the second communication method (step S132: NO), it terminates this series of processes. In step S132, if the processing unit 11 determines that the communication device can switch to the second communication method (step S132: YES), it proceeds to step S133. In step S133, the processing unit 11 transmits an interference signal. This process corresponds to the process performed by the first communication device 10 in the upper part of Figure 15.

[0197] The second modified example, the communication network system 100, is installed in a vehicle. The jamming device monitors the status of the vehicle. When the jamming device receives a jamming request signal, it transmits a jamming signal based on the vehicle status it has monitored.

[0198] In the second modified communication network system 100, when the jamming device receives a jamming request signal, it decides whether or not to transmit a jamming signal depending on the vehicle's status. This allows the second modified communication network system 100 to prioritize securing data transmission opportunities by refraining from transmitting jamming signals depending on the vehicle's status.

[0199] In the above embodiment, the first communication device 10 in the communication network system 100 switches the communication method of the communication device to the second communication method by transmitting an interference signal. Alternatively, the management device 50 in the communication network system 100 may switch the communication method of the communication device to the second communication method by stopping the transmission of the start signal 40.

[0200] Figure 18 shows a specific example of communication when the first communication device 10, the second communication device 20, and the management device 50 in the third modified communication network system 100 switch the communication method to the second communication method. The first communication device 10, the second communication device 20, and the management device 50 in the third modified communication network system 100 perform the communication shown in Figure 18 instead of the communication method shown in Figure 8.

[0201] The communication shown in Figure 18 is executed when the same two conditions as in Figure 8 are met. When both conditions are met, the management device 50 stops transmitting the start signal 40, as shown in the upper part of Figure 18. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0202] As shown in the middle section of Figure 8, the first communication device 10, the second communication device 20, and the management device 50 switch to the second communication method if they do not detect a start signal for a predetermined period of time. In this way, each communication device in the communication network system 100 of the third modified example switches the communication method from the first communication method to the second communication method.

[0203] The communication pattern after the communication device switches to the second communication method is the same as in Figure 8. In the third modified example, the first communication device 10 does not need to be a jamming device. Therefore, in the third modified example, the first communication device 10 does not perform the series of processes shown in Figure 10.

[0204] In the third modification example, the management device 50 acquires the status of communication errors in the communication network system 100 on behalf of the first communication device 10 in order to stop transmitting the start signal 40 as needed. At this time, the management device 50 acquires information as the status of communication errors, which is the number of communication errors that occurred while each communication device transmitted data a predetermined number of times, similar to the first communication device 10 in this embodiment. Also, in the third modification example, a default value is set for each communication device, similar to this embodiment.

[0205] Figure 19 shows a series of processes performed by the management device 50 when it stops transmitting the start signal 40. The program stored in the storage device 52 of the management device 50 includes a program that controls the communication methods of multiple communication devices in the third modified communication network system 100. This series of processes is performed by the processing unit 51 of the management device 50 processing according to the program stored in the storage device 52. This series of processes is performed when the management device 50 obtains information on the number of communication errors that occurred while transmitting data a predetermined number of times to either the first communication device 10, the second communication device 20, or the management device 50 itself.

[0206] As shown in Figure 19, once this series of processes is initiated, in step S141, the processing unit 51 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value. This process is the same as the process executed by the processing unit 11 in step S101 in Figure 10.

[0207] In the process of step S141, if the processing unit 51 determines that the number of communication errors is not equal to or greater than a predetermined value (step S141: NO), it terminates this series of processes. In the process of step S141, if the processing unit 51 determines that the number of communication errors is equal to or greater than a predetermined value (step S141: YES), it proceeds to step S142.

[0208] In step S142, the processing unit 51 grasps the status of the vehicle. This process is the same as the process performed by the processing unit 11 in step S102 in Figure 10. In the next step, S143, the processing unit 51 determines whether the communication device in the communication network system 100 of the third modified example can switch to the second communication method. This process is the same as the process performed by the processing unit 11 in step S103 of Figure 10. Therefore, the processing unit 51 determines, for example, that the communication device cannot switch to the second communication method when the vehicle is in automatic driving mode. Also, the processing unit 51 determines, for example, that the communication device cannot switch to the second communication method when the vehicle is undergoing fault diagnosis.

[0209] In step S143, if the processing unit 51 determines that the communication device is not capable of switching to the second communication method (step S143: NO), it terminates this series of processes. In step S143, if the processing unit 51 determines that the communication device can switch to the second communication method (step S143: YES), it proceeds to step S144. In step S144, the processing unit 51 stops transmitting the start signal 40. This process corresponds to the process performed by the management device 50 in the upper part of Figure 18. In this way, the processing unit 51 stops transmitting the start signal 40 based on the acquired communication error status and the vehicle status it has grasped.

[0210] The third modified communication network system 100 is composed of multiple communication devices. The third modified communication network system 100 and the vehicle equipped with the third modified communication network system 100 are equipped with a management device 50 that transmits a start signal 40 to the multiple communication devices. The multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal 40. The management device 50 stops transmitting the start signal 40 depending on the status of communication errors in the third modified communication network system 100. If the multiple communication devices do not sense the start signal 40 for a predetermined period of time, they switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order.

[0211] In the third modified example of the communication network system 100 and the vehicle equipped with the communication network system 100, the management device 50 stops transmitting the start signal 40 depending on the status of the communication error. As a result, in the third modified example of the communication network system 100 and the vehicle equipped with the communication network system 100, the communication method switches from the first communication method to the second communication method.

[0212] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order. As a result, the communication network system 100 of the third modified example and the vehicle equipped with the communication network system 100 can suppress communication errors that occur in specific communication devices.

[0213] The management device 50 acquires the status of communication errors in the communication network system 100 of the third modified example. Based on the acquired communication error status, the management device 50 stops transmitting the start signal 40.

[0214] In the third modified example of the communication network system 100, the management device 50 stops transmitting a start signal based on the communication error status it has acquired. This allows the third modified example of the communication network system 100 to switch the communication method of each communication device to the second communication method in response to the communication error status.

[0215] The third modified example communication network system 100 is installed in a vehicle. The management device 50 monitors the status of the vehicle. Based on the acquired communication error status and the monitored vehicle status, the management device 50 stops transmitting the start signal 40.

[0216] In the third modified example of the communication network system 100, the management device 50 decides whether or not to stop transmitting the start signal depending on the vehicle status. As a result, the third modified example of the communication network system 100 can prioritize securing the opportunity to transmit data by not stopping the start signal 40 depending on the vehicle status.

[0217] In the third modified communication network system 100, the management device 50 acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times, as a status of communication errors. In the third modified communication network system 100, the management device 50 acquires information on the frequency of communication errors in each communication device, as a status of communication errors. As a result, the third modified communication network system 100 can switch the communication method of the communication device to the second communication method according to the frequency of communication errors in the communication device.

[0218] In the third modified example of the communication network system 100, the management device 50 stops transmitting the start signal 40 when the number of communication errors acquired as a communication error status exceeds a predetermined value. As a result, the third modified example of the communication network system 100 can switch the communication method to the second communication method when the frequency of communication errors exceeds a predetermined frequency.

[0219] Default values ​​are set for each communication device. In the third modified example of the communication network system 100, the management device 50 stops transmitting the start signal 40 when the number of communication errors for any communication device exceeds a default value.

[0220] In the third modified example of the communication network system 100, the management device 50 stops transmitting a start signal if the number of communication errors of any communication device exceeds a corresponding default value. This allows the third modified example of the communication network system 100 to switch to the second communication method while closely monitoring the communication error status of each communication device.

[0221] In the third modified example of the communication network system 100, the management device 50 does not stop transmitting the start signal if the detected vehicle status indicates that it is in autonomous driving mode. In other words, the third modified example of the communication network system 100 does not switch the communication method to the second communication method when the vehicle is in autonomous driving mode. This ensures that each communication device has an opportunity to communicate. That is, the third modified example of the communication network system 100 can prevent the execution of autonomous driving by the vehicle from being hindered by switching the communication method to the second communication method.

[0222] In the third modified communication network system 100, the management device 50 does not stop transmitting the start signal 40 if the detected vehicle status is undergoing fault diagnosis. In other words, the third modified communication network system 100 does not switch the communication method to the second communication method when a vehicle is undergoing fault diagnosis. This ensures that each communication device has an opportunity to communicate. That is, the third modified communication network system 100 can prevent the execution of fault diagnosis by the vehicle from being hindered by switching the communication method to the second communication method.

[0223] The management device 50 transmits a start signal 40 to the communication network system 100 of the third modified example, which is composed of multiple communication devices. After sensing the start signal 40, the multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order. On the other hand, if the multiple communication devices do not sense the start signal 40 for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order. The management device 50 stops transmitting the start signal 40 depending on the status of the communication error in the communication network system 100 of the third modified example.

[0224] The management device 50 stops transmitting the start signal 40 depending on the status of the communication error. As a result, in the third modified example of the communication network system 100, the communication method switches from the first communication method to the second communication method.

[0225] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0226] This allows the management device 50 to suppress communication errors that occur in specific communication devices. The program is applied to a management device 50 that transmits a start signal 40 in a third modified communication network system 100, which is composed of multiple communication devices. The multiple communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after sensing the start signal 40. On the other hand, if the multiple communication devices do not sense the start signal 40 for a predetermined period of time, they are configured to switch to a second communication method in which they transmit data when other communication devices are not transmitting data, regardless of the predetermined order. The program causes the management device 50 to stop transmitting the start signal 40 based on the communication error status in the third modified communication network system 100.

[0227] The program stops sending the start signal 40 to the management device 50 depending on the communication error status. As a result, in the third modified example of the communication network system 100, the communication method switches from the first communication method to the second communication method.

[0228] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0229] This allows the program to suppress communication errors that occur in specific communication devices. In the above embodiment, the program is stored in the storage device 52 of the management device 50. The program may also be provided in a state recorded on a recording medium. Examples of recording media on which the program is recorded include memory such as USB memory, SSD, and SD card, as well as CD-ROMs and optical discs.

[0230] The third modified communication network system 100 is composed of multiple communication devices. The third modified communication network system 100 includes a management device 50 that transmits a start signal 40. The multiple communication devices communicate with each other using a first communication method in which they transmit their respective data in a predetermined order after sensing the start signal 40. The communication method is the communication method in such a communication network system of the third modified example. The communication method includes a step (step S144) in which the management device 50 stops transmitting the start signal 40 based on the status of a communication error in the third modified communication network system 100. The communication method includes a step (step S31) in which, if the state of not sensing the start signal 40 continues for a predetermined time, the multiple communication devices switch to a second communication method in which they transmit data regardless of a predetermined order, when other communication devices are not transmitting data.

[0231] In the third modified example of the communication network system 100, the communication method involves stopping the transmission of the start signal 40 to the management device 50 depending on the status of the communication error. As a result, in the third modified example of the communication network system 100, the communication method switches from the first communication method to the second communication method.

[0232] In the first communication method, each communication device transmits data in a predetermined order. On the other hand, in the second communication method, communication devices can transmit data regardless of the predetermined order.

[0233] This allows the communication method to suppress communication errors that occur in specific communication devices. In the third example of modification, the management device 50 acquires the communication error status for all communication devices in the communication network system 100. Alternatively, the management device 50 may acquire the communication error status for only specific communication devices.

[0234] In the third example of modification, the management device 50 acquires the communication error status for each communication device in the communication network system 100. Alternatively, the management device 50 may acquire the communication error status for the entire communication network system 100.

[0235] In this case, the management device 50 acquires information as the status of communication errors, specifically the number of communication errors that occurred in the communication network system 100 of the third modified example while data was transmitted a predetermined number of times.

[0236] In this case, in the third modified communication network system 100, the management device 50 acquires information about the frequency of communication errors occurring throughout the entire third modified communication network system 100 as a status of communication errors. As a result, the third modified communication network system 100 can switch the communication method of the communication device to the second communication method according to the frequency of communication errors occurring in the data transmitted by the third modified communication network system 100.

[0237] In the third modified example, the management device 50 stops transmitting the start signal 40 based on the communication error status it has acquired. Alternatively, the management device 50 may stop transmitting the start signal 40 based on a request from another communication device that has acquired the communication error status, rather than acquiring the communication error status itself.

[0238] Figure 20 shows a specific example of communication when the first communication device 10, the second communication device 20, and the management device 50 in the fourth modified communication network system 100 switch the communication method to the second communication method. The first communication device 10, the second communication device 20, and the management device 50 in the fourth modified communication network system 100 execute the communication shown in Figure 20, changing from the communication method shown in Figure 8.

[0239] The communication shown in Figure 20 is executed when the same two conditions as in Figure 8 are met. When both conditions are met, the first communication device 10 sends a stop request signal to the management device 50, as shown in the upper part of Figure 20. The stop request signal is a signal that requests the management device 50 to stop sending the start signal 40. Thus, in this example, in the fourth modified example, the first communication device 10 has become a stop request device that sends a stop request signal depending on the status of the communication error.

[0240] As shown in the upper part of Figure 20, the management device 50 stops transmitting the start signal 40 after receiving the stop request signal. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0241] As shown in the middle section of Figure 20, the first communication device 10, the second communication device 20, and the management device 50 switch to the second communication method if they do not detect a start signal for a predetermined period of time. In this way, the communication devices in the communication network system 100 of the fourth modified example switch the communication method to the second communication method.

[0242] The communication pattern after the communication device switches to the second communication method is the same as in Figure 8. In the fourth modification example, as in the third modification example, the first communication device 10 does not need to be a jamming device. Therefore, in the fourth modification example, the first communication device 10 does not perform the series of processes shown in Figure 10.

[0243] In the fourth modified example, the first communication device 10 acquires the status of communication errors in the communication network system 100 in order to transmit a stop request signal as needed. At this time, the first communication device 10 acquires information as the number of communication errors that occurred while each communication device transmitted data a predetermined number of times, as in the above embodiment, as the status of communication errors. Also in the fourth modified example, as in the above embodiment, a default value is set for each communication device.

[0244] Figure 21 shows a series of processes performed when the first communication device 10 transmits a stop request signal. This series of processes is performed by the processing unit 11 of the first communication device 10. This series of processes is performed when the first communication device 10 obtains information on the number of communication errors that occurred during the transmission of data a predetermined number of times to either the first communication device 10 itself, the second communication device 20, or the management device 50.

[0245] As shown in Figure 21, once this series of processes is initiated, in step S151, the processing unit 11 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value. This process is the same as the process in step S101 in Figure 10.

[0246] In the process of step S151, if the processing unit 11 determines that the number of communication errors is not equal to or greater than a predetermined value (step S151: NO), it terminates this series of processes. In the process of step S151, if the processing unit 21 determines that the number of communication errors is equal to or greater than a predetermined value (step S151: YES), it proceeds to step S152.

[0247] In step S152, the processing unit 11 grasps the status of the vehicle. This process is the same as the process in step S102 in Figure 10. In the next step, S153, the processing unit 11 determines whether the communication device in the communication network system 100 of the fourth modified example can switch to the second communication method. This process is the same as the process in step S103 in Figure 10. Therefore, for example, the processing unit 11 determines that the communication device cannot switch to the second communication method if the vehicle is in automatic driving mode. Similarly, the processing unit 21 determines that the communication device cannot switch to the second communication method if the vehicle is undergoing fault diagnosis.

[0248] In the process of step S153, if the processing unit 11 determines that the communication device is not capable of switching to the second communication method (step S153: NO), it terminates this series of processes. In step S153, if the processing unit 11 determines that the communication device can switch to the second communication method (step S153: YES), it proceeds to step S154. In step S154, the processing unit 11 transmits a stop request signal. At this time, the processing unit 11 transmits the stop request signal according to the first communication method. This process corresponds to the process performed by the first communication device 10 in the upper part of Figure 20. In this way, the processing unit 11 transmits the stop request signal based on the acquired communication error status and the vehicle status it has grasped.

[0249] Upon receiving the stop request signal, the control device 50 stops transmitting the start signal 40 in response to the stop request signal. The fourth modified version of the communication network system 100 includes a stop request device that sends a stop request signal to the management device 50 requesting it to stop transmitting the start signal 40. The stop request device acquires the status of communication errors in the fourth modified version of the communication network system 100. Based on the acquired status of communication errors, the stop request device sends a stop request signal. When the management device 50 receives the stop request signal, it stops transmitting the start signal 40.

[0250] In the fourth modified example of the communication network system 100, the stop request device stops transmitting the start signal 40 to the management device 50 according to the status of the acquired communication error. As a result, the fourth modified example of the communication network system 100 can switch the communication method of the communication device to the second communication method in response to the status of the communication error.

[0251] The fourth modified example, the communication network system 100, is installed in a vehicle. The stop request device monitors the status of the vehicle. Based on the acquired communication error status and the monitored vehicle status, the stop request device transmits a stop request signal.

[0252] In the fourth modified example of the communication network system 100, the stop request device decides whether or not to transmit a stop request signal depending on the vehicle's status. This allows the fourth modified example of the communication network system 100 to prioritize securing data transmission opportunities by refraining from transmitting a stop request signal depending on the vehicle's status.

[0253] In the fourth modified example of the communication network system 100, the stop request device acquires information on the number of communication errors that occurred while each communication device transmitted data a predetermined number of times, as a status of communication errors. In the fourth modified example of the communication network system 100, the stop request device acquires information on the frequency of communication errors occurring in each communication device, as a status of communication errors. As a result, the fourth modified example of the communication network system 100 can switch the communication method of each communication device to the second communication method according to the frequency of communication errors occurring in each communication device.

[0254] In the fourth modified example of the communication network system 100, the stop request device transmits a stop request signal when the number of communication errors obtained as a communication error status exceeds a predetermined value. In the fourth modified example of the communication network system 100, the stop request device transmits a stop request signal when the number of communication errors exceeds a predetermined value. As a result, the fourth modified example of the communication network system 100 can switch the communication method to the second communication method when the frequency of communication errors exceeds a predetermined frequency.

[0255] Default values ​​are set for each communication device. In the fourth modified example of the communication network system 100, the stop request device transmits a stop request signal when the number of communication errors for any communication device exceeds a default value. In the fourth modified example of the communication network system 100, the stop request device transmits a stop request signal when the number of communication errors for any communication device exceeds the corresponding default value. This allows the fourth modified example of the communication network system 100 to switch the communication method to the second communication method while closely monitoring the communication error status for each communication device.

[0256] In the fourth modified example of the communication network system 100, the stop request device does not transmit a stop request signal if the detected vehicle status indicates that the vehicle is in autonomous driving mode. In other words, the fourth modified example of the communication network system 100 does not switch the communication method to the second communication method when the vehicle is in autonomous driving mode. This ensures that each communication device has an opportunity to communicate. That is, the fourth modified example of the communication network system 100 can prevent the execution of autonomous driving by the vehicle from being hindered by switching the communication method to the second communication method.

[0257] In the communication network system 100 of the fourth modification example, when the status of the vehicle grasped by the stop request device is during a fault diagnosis, the stop request signal is not transmitted. That is, in the communication network system 100 of the fourth modification example, when the vehicle is undergoing a fault diagnosis, the communication method is not switched to the second communication method. Thereby, the communication network system 100 of the fourth modification example can guarantee the communication opportunities for each communication device. That is, the communication network system 100 of the fourth modification example can suppress the situation where the execution of the fault diagnosis by the vehicle is hindered by switching the communication method to the second communication method.

[0258] · In the fourth modification example, the first communication device 10 as the stop request device acquires the communication error status for all the communication devices in the communication network system 100. On the other hand, the first communication device 10 may acquire the communication error status only for a specific communication device.

[0259] · In the fourth modification example, the first communication device 10 as the stop request device acquires the communication error status for each communication device in the communication network system 100. On the other hand, the first communication device 10 may acquire the communication error status of the entire communication network system 100.

[0260] In this case, as the communication error status, the stop request device acquires information on the number of communication errors that occurred while data was transmitted a predetermined number of times in the communication network system 100 of the fourth modification example.

[0261] In this case, in the communication network system 100 of the fourth modification example, as the communication error status, the stop request device acquires information on the occurrence frequency of communication errors in the entire communication network system 100 of the fourth modification example. Thereby, the communication network system 100 of the fourth modification example can switch the communication method of the communication device to the second communication method according to the occurrence frequency of communication errors in the data transmitted in the communication network system 100 of the fourth modification example.

[0262] In the fourth modified example, the first communication device 10, which is a stop request device, transmits a jamming request signal based on the acquired error status and the vehicle status it has grasped. Alternatively, the first communication device 10, as a stop request device, may transmit a stop request signal based only on the acquired error status without knowing the vehicle status. In this case, the management device 50, upon receiving the stop request signal, grasps the vehicle status and then stops transmitting the start signal 40 based on the vehicle status.

[0263] Figure 22 shows a specific example of communication when the first communication device 10, the second communication device 20, and the management device 50 in the fifth modified communication network system 100 switch the communication method to the second communication method. The first communication device 10, the second communication device 20, and the management device 50 in the fifth modified communication network system 100 execute the communication shown in Figure 22, changing from the communication mode shown in Figure 8.

[0264] In the communication shown in Figure 22, the first communication device 10 sends a stop request signal to the management device 50 if the number of communication errors that occur while any of the communication devices in the communication network system 100 transmit data a predetermined number of times exceeds a predetermined value.

[0265] Upon receiving the stop request signal, the management device 50 stops transmitting the start signal 40 if the communication device is capable of switching to the second communication method. As a result, the first communication device 10, the second communication device 20, and the management device 50 no longer detect the start signal 40.

[0266] As shown in the middle section of Figure 22, the first communication device 10, the second communication device 20, and the management device 50 switch to the second communication method if they do not detect a start signal for a predetermined period of time. In this way, the communication devices in the communication network system 100 of the fifth modified example switch the communication method to the second communication method.

[0267] The communication pattern after the communication device switches to the second communication method is the same as in Figure 8. In the fifth modification example, as in the third and fourth modifications examples, the first communication device 10 does not need to be a jamming device. Therefore, in the fifth modification example, the first communication device 10 does not perform the series of processes shown in Figure 10.

[0268] Figure 23 shows a series of processes performed when the first communication device 10 transmits a stop request signal. This series of processes is performed by the processing unit 11 of the first communication device 10. This series of processes is performed when the first communication device 10 obtains information on the number of communication errors that occurred during the transmission of data a predetermined number of times to either the first communication device 10 itself, the second communication device 20, or the management device 50.

[0269] As shown in Figure 23, once this series of processes is initiated, in step S161, the processing unit 11 determines whether the number of communication errors in the communication device that acquired the information is equal to or greater than a predetermined value. This process is the same as the process in step S101 in Figure 10.

[0270] In the process of step S161, if the processing unit 11 determines that the number of communication errors is not equal to or greater than a predetermined value (step S161: NO), it terminates this series of processes. In step S161, if the processing unit 11 determines that the number of communication errors is equal to or greater than a predetermined value (step S161: YES), it proceeds to step S162. In step S162, the processing unit 21 transmits a stop request signal. At this time, the processing unit 11 transmits the stop request signal according to the first communication method. This process corresponds to the process performed by the first communication device 10 in the upper part of Figure 22.

[0271] Figure 24 shows the sequence of processes when the control device 50 stops transmitting the start signal. This sequence of processes is executed by the processing unit 51 of the control device 50. This sequence of processes is executed when the control device 50 receives a stop request signal.

[0272] As shown in Figure 24, once this series of processes begins, in step S171, the processing unit 51 grasps the status of the vehicle. This process is the same as the process performed by the processing unit 11 in step S102 in Figure 10.

[0273] In the next step, S172, the processing unit 51 determines whether the communication device in the communication network system 100 of the fifth modified example can be switched to the second communication method. This process is the same as the process performed by the processing unit 11 in step S103 of Figure 10.

[0274] In the process of step S172, if the processing unit 51 determines that the communication device is not capable of switching to the second communication method (step S172: NO), it terminates this series of processes. In step S172, if the processing unit 51 determines that the communication device can switch to the second communication method (step S172: YES), it proceeds to step S173. In step S173, the processing unit 51 stops transmitting the start signal 40. This process corresponds to the process performed by the management device 50 in the upper part of Figure 22.

[0275] The communication network system 100 is installed in the vehicle. The management device 50 monitors the status of the vehicle. When the management device 50 receives a stop request signal, it stops transmitting a start signal based on the vehicle status it has monitored.

[0276] In the fifth modified example of the communication network system 100, the stop request device decides whether or not to stop transmitting the start signal 40 depending on the vehicle's status. This allows the fifth modified example of the communication network system 100 to prioritize securing data transmission opportunities by not stopping the transmission of the start signal 40 depending on the vehicle's status.

[0277] <Note> The technical concepts that can be understood from the above embodiments and modified examples are described below. [Appendix 1] A communication network system composed of a plurality of communication devices, the communication network system includes a management device that transmits a start signal to the plurality of communication devices, and an interference device that transmits an interference signal for interfering with the detection of the start signal by the plurality of communication devices, the plurality of communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after detecting the start signal, the interference device transmits the interference signal according to the communication error situation in the communication network system, and when the state of not detecting the start signal by the plurality of communication devices continues for a predetermined time, the communication method is switched to a second communication method in which data is transmitted when other communication devices are not transmitting data regardless of the predetermined order.

[0278] [Appendix 2] The interference device in the communication network system according to [Appendix 1], which acquires the communication error situation in the communication network system and transmits the interference signal based on the acquired communication error situation.

[0279] [Appendix 3] The communication network system is mounted on a vehicle, and the interference device in the communication network system according to [Appendix 2] transmits the interference signal based on the acquired communication error situation and the grasped vehicle situation.

[0280] [Appendix 4] The interference device in the communication network system according to [Appendix 2] or [Appendix 3], which acquires, as the communication error situation, information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times.

[0281] [Appendix 5] The interference device in the communication network system according to [Appendix 2] or [Appendix 3], which acquires, as the communication error situation, information on the number of communication errors that occurred while data was transmitted a predetermined number of times in the communication network system.

[0282] [Note 6] The communication network system described in [Note 4] or [Note 5], wherein the jamming device transmits the jamming signal when the number of communication errors obtained as the status of the communication errors exceeds a predetermined value.

[0283] [Note 7] A default value is set for each communication device, and the jamming device transmits the jamming signal when the number of communication errors for any of the communication devices exceeds the default value. The communication network system as described in [Note 4].

[0284] [Note 8] The communication network system is further comprising a jamming request device that transmits a jamming request signal to the jamming device, the jamming request device acquires the status of the communication error in the communication network system, transmits the jamming request signal based on the acquired status of the communication error, and the jamming device transmits the jamming signal when it receives the jamming request signal.

[0285] [Note 9] The communication network system is mounted on a vehicle, and the jamming request device grasps the status of the vehicle and transmits the jamming request signal based on the acquired status of the communication error and the grasped status of the vehicle, as described in [Note 8].

[0286] [Note 10] The communication network system is mounted on a vehicle, and the jamming device grasps the status of the vehicle and, upon receiving the jamming request signal, transmits the jamming signal based on the vehicle status it has grasped.

[0287] [Note 11] The communication network system according to any one of [Note 8] to [Note 10], wherein the jamming request device acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times as the status of the communication error.

[0288] [Note 12] The communication network system described in any one of [Note 8] to [Note 10], wherein the interference request device acquires information on the number of communication errors that occurred in the communication network system while data was transmitted a predetermined number of times, as the status of the communication error.

[0289] [Note 13] The communication network system described in [Note 11] or [Note 12], wherein the interference request device transmits the interference request signal when the number of communication errors obtained as the status of the communication errors is equal to or greater than a predetermined value.

[0290] [Note 14] A default value is set for each communication device, and the interference request device transmits the interference request signal when the number of communication errors for any of the communication devices exceeds the default value. The communication network system as described in [Note 11].

[0291] [Note 15] The communication network system described in any one of [Notes 3] to [Note 7] and [Notes 10] to [Note 14], wherein the jamming device does not transmit the jamming signal if the detected status of the vehicle is in automatic driving mode.

[0292] [Note 16] The communication network system described in any one of [Notes 3] to [Note 7] and [Notes 10] to [Note 14], wherein the jamming device does not transmit the jamming signal if the detected vehicle status is undergoing fault diagnosis.

[0293] [Note 17] The communication network system described in any one of [Note 9] and [Note 11] to [Note 14], wherein the interference request device does not transmit the interference request signal if the detected status of the vehicle is in automatic driving mode.

[0294] [Note 18] The communication network system described in any one of [Note 9] and [Note 11] to [Note 14], in which the interference request device does not transmit the interference request signal if the detected status of the vehicle is undergoing fault diagnosis.

[0295] [Note 19] A jamming device applied to a communication network system comprising a plurality of communication devices and a management device that transmits a start signal to the communication devices, wherein the plurality of communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal, but if the state of not sensing the start signal continues for a predetermined time, the device is configured to switch to a second communication method in which the communication device transmits data when no other communication device is transmitting data, regardless of the predetermined order, and the jamming device transmits a jamming signal that interferes with the sensing of the start signal by the communication devices depending on the communication error situation in the communication network system.

[0296] [Note 20] An interference device according to [Note 19] that acquires the status of the communication error in the communication network system and transmits the interference signal based on the acquired status of the communication error.

[0297] [Note 21] The communication network system is mounted on a vehicle, and the jamming device described in [Note 20] grasps the status of the vehicle and transmits the jamming signal based on the status of the acquired communication error and the status of the vehicle grasped.

[0298] [Note 22] The jamming device described in [Note 20] or [Note 21] acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times, as the status of the communication error.

[0299] [Note 23] The jamming device described in [Note 20] or [Note 21] acquires information on the number of communication errors that occurred in the communication network system while data was transmitted a predetermined number of times, as the status of the communication error.

[0300] [Note 24] The jamming device described in [Note 22] or [Note 23] transmits the jamming signal when the number of communication errors obtained as the status of the communication error is equal to or greater than a predetermined value. [Note 25] A jamming device as described in [Note 22], wherein a default value is set for each communication device, and the jamming signal is transmitted when the number of communication errors for any of the communication devices exceeds the default value.

[0301] [Note 26] If the detected status of the vehicle is in automatic driving mode, the jamming device described in any one of [Note 21] to [Note 25] does not transmit the jamming signal. [Note 27] If the vehicle's status is determined to be undergoing fault diagnosis, the jamming device described in any one of [Note 21] to [Note 25] does not transmit the jamming signal.

[0302] [Note 28] A communication network system comprising a plurality of communication devices, wherein the communication network system includes a management device that transmits a start signal to the plurality of communication devices, the plurality of communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal, the management device stops transmitting the start signal according to the status of communication errors in the communication network system, and the plurality of communication devices switch their communication method to a second communication method in which they transmit data when no other communication device is transmitting data, regardless of the predetermined order, if the state of not sensing the start signal continues for a predetermined time.

[0303] [Note 29] The communication network system described in [Note 28], wherein the management device acquires the status of the communication error in the communication network system and stops transmitting the start signal based on the acquired status of the communication error.

[0304] [Note 30] The communication network system is installed in a vehicle, and the management device grasps the status of the vehicle and stops transmitting the start signal based on the status of the acquired communication error and the status of the vehicle grasped, as described in [Note 29].

[0305] [Note 31] The communication network system described in [Note 29] or [Note 30], wherein the management device acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times, as the status of the communication error.

[0306] [Note 32] The management device acquires information on the number of communication errors that occurred in the communication network system while data was transmitted a predetermined number of times, as the status of the communication errors. [Note 29] or [Note 30] The communication network system as described in [Note 30].

[0307] [Note 33] The communication network system according to [Note 31] or [Note 32], wherein the management device stops transmitting the start signal when the number of communication errors obtained as the status of the communication error is equal to or greater than a predetermined value.

[0308] [Note 34] A default value is set for each communication device, and the management device stops transmitting the start signal when the number of communication errors for any of the communication devices exceeds the default value. This is the communication network system described in [Note 31].

[0309] [Note 35] The communication network system is further comprising a stop request device that transmits a stop request signal to the management device requesting it to stop transmitting the start signal, the stop request device acquires the status of the communication error in the communication network system, transmits the stop request signal based on the acquired status of the communication error, and the management device stops transmitting the start signal when it receives the stop request signal, as described in [Note 28].

[0310] [Note 36] The communication network system is installed in a vehicle, and the stop request device grasps the status of the vehicle and transmits the stop request signal based on the acquired status of the communication error and the grasped status of the vehicle, as described in [Note 35].

[0311] [Note 37] The communication network system is installed in a vehicle, and the management device grasps the status of the vehicle and, upon receiving the stop request signal, stops transmitting the start signal based on the vehicle status it has grasped, as described in [Note 35].

[0312] [Note 38] The communication network system described in any one of [Notes 35] to [Note 37], wherein the stop request device acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times as the status of the communication error.

[0313] [Note 39] The communication network system described in any one of [Notes 35] to [Note 37], wherein the stop request device acquires information on the number of communication errors that occurred in the communication network system while data was transmitted a predetermined number of times, as the status of the communication error.

[0314] [Note 40] The communication network system described in [Note 38] or [Note 39], wherein the stop request device transmits the stop request signal when the number of communication errors obtained as the status of the communication error is equal to or greater than a predetermined value.

[0315] [Note 41] A default value is set for each communication device, and the stop request device transmits the stop request signal when the number of communication errors for any of the communication devices exceeds the default value. The communication network system as described in [Note 38].

[0316] [Note 42] The management device shall not stop transmitting the start signal if the vehicle status it has ascertained is in automatic operation. [Notes 30] to [Note 34] and [Notes 37] to

[41] The communication network system described above.

[0317] [Note 43] The communication network system described in any one of [Notes 30] to [Note 34] and [Notes 37] to

[41] , wherein the management device does not stop transmitting the start signal if the vehicle status it has grasped is undergoing fault diagnosis.

[0318] [Note 44] The communication network system described in any one of [Note 36] and [Note 38] to [Note 41], wherein the stop request device does not transmit the stop request signal if the detected status of the vehicle is in automatic operation.

[0319] [Note 45] The communication network system described in any one of [Note 36] and [Note 38] to [Note 41], wherein the stop request device does not transmit the stop request signal if the detected vehicle status is undergoing fault diagnosis.

[0320] [Note 46] A management device that transmits a start signal in a communication network system composed of multiple communication devices, wherein the multiple communication devices communicate with each other using a first communication method in which each communication device transmits data in a predetermined order after sensing the start signal, but if the state of not sensing the start signal continues for a predetermined time, the management device is set to switch to a second communication method in which data is transmitted when no other communication device is transmitting data, regardless of the predetermined order, and stops transmitting the start signal depending on the communication error situation in the communication network system.

[0321] [Appendix 47] The management device described in [Appendix 46], which acquires the status of the communication error in the communication network system and stops transmitting the start signal based on the acquired status of the communication error.

[0322] [Note 48] The communication network system is mounted on a vehicle and is a management device as described in [Note 47] that grasps the status of the vehicle and stops transmitting the start signal based on the status of the acquired communication error and the status of the vehicle grasped.

[0323] [Note 49] The management device described in [Note 47] or [Note 48] acquires information on the number of communication errors that occurred while the communication device transmitted data a predetermined number of times, as the status of the communication error.

[0324] [Note 50] A management device as described in [Note 47] or [Note 48] that acquires information on the number of communication errors that occurred in the communication network system while data was transmitted a predetermined number of times, as the status of the communication errors.

[0325] [Note 51] The management device described in [Note 49] or [Note 50] stops transmitting the start signal if the number of communication errors obtained as the status of the communication errors is equal to or greater than a predetermined value.

[0326] [Note 52] A management device as described in [Note 49], wherein a default value is set for each communication device, and the transmission of the start signal is stopped when the number of communication errors for any of the communication devices exceeds the default value.

[0327] [Note 53] The management device described in any one of [Notes 48] to [Note 52], which does not stop transmitting the start signal if the vehicle status it has been determined to be in automatic operation. [Note 54] If the status of the vehicle as determined is in the process of fault diagnosis, the control device described in any one of [Note 48] to [Note 52] does not stop transmitting the start signal.

[0328] [Note 55] The communication network system described in any one of [Note 1] to [Note 18] and [Note 28] to [Note 45], wherein when the communication method is switched from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, the communication device sets an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data, and starts the transmission of the data when the set offset time has elapsed.

[0329] [Note 56] The communication network system described in any one of [Notes 1] to [Note 18] and [Note 28] to [Note 45], wherein when the communication method is switched from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, the offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data is set to be shorter as the capacity of the data to be transmitted increases, and the transmission of the data is started when the set offset time has elapsed.

[0330] [Note 57] Each of the aforementioned communication devices has a predetermined priority, and when the communication device switches the communication method from the first communication method to the second communication method, if there is data to be transmitted immediately after switching to the second communication method, the offset time from the moment the communication method is switched to the second communication method until the start of transmission of the said data is set to be shorter for higher priority devices, and the transmission of the said data is started when the set offset time has elapsed, as described in any one of [Note 1] to [Note 18] and [Note 28] to [Note 45]. [Explanation of symbols]

[0331] 10…First communication device 11… Processing Unit 12...Storage device 20...Second communication device 21… Processing Unit 22...Storage device 30... Communications bus 40…Start signal 41…First Data 42…Second data 43…Third data 50…Management device 51… Processing Unit 52...Storage device 100... Communication Network System

Claims

1. A communication network system composed of multiple communication devices, The aforementioned communication network system is A management device that transmits a start signal to the aforementioned multiple communication devices, The system includes a jamming device that transmits a jamming signal that interferes with the detection of the start signal by the plurality of communication devices, The aforementioned multiple communication devices are, After sensing the aforementioned start signal, each communication device communicates with the others using a first communication method in which it transmits data in a predetermined order. The aforementioned jamming device is The interference signal is transmitted according to the status of the communication error in the aforementioned communication network system. The aforementioned multiple communication devices are, If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the communication method is switched to a second communication method in which data is transmitted when no other communication device is transmitting data. Communication network system.

2. The aforementioned jamming device is The status of the communication error in the aforementioned communication network system is acquired. Based on the acquired communication error status, the interference signal is transmitted. The communication network system according to claim 1.

3. The aforementioned communication network system is installed in the vehicle. The aforementioned jamming device is Assess the status of the aforementioned vehicle, The interference signal is transmitted based on the acquired communication error status and the assessed status of the vehicle. The communication network system according to claim 2.

4. The aforementioned jamming device is The aforementioned communication error situation is as follows: The communication device acquires information on the number of communication errors that occurred while it was transmitting data a predetermined number of times. The communication network system according to claim 2.

5. The aforementioned jamming device is The aforementioned communication error situation is as follows: The communication network system acquires information on the number of communication errors that occurred during a predetermined number of data transmissions. The communication network system according to claim 2.

6. The aforementioned jamming device is The interference signal is transmitted when the number of communication errors, as determined by the communication error status, exceeds a predetermined value. A communication network system according to claim 4 or claim 5.

7. Default values ​​are set for each communication device. The aforementioned jamming device is The interference signal is transmitted when the number of communication errors for any of the aforementioned communication devices exceeds the predetermined value. The communication network system according to claim 4.

8. The aforementioned communication network system is The system includes a jamming request device that transmits a jamming request signal to the jamming device, which requests the transmission of the jamming signal. The aforementioned interference request device is The status of the communication error in the aforementioned communication network system is acquired. Based on the acquired communication error status, the interference request signal is transmitted. The aforementioned jamming device is When the aforementioned interference request signal is received, the interference signal is transmitted. The communication network system according to claim 1.

9. The aforementioned communication network system is installed in the vehicle. The aforementioned interference request device is Assess the status of the aforementioned vehicle, The interference request signal is transmitted based on the acquired communication error status and the assessed vehicle status. The communication network system according to claim 8.

10. The aforementioned communication network system is installed in the vehicle. The aforementioned jamming device is Assess the status of the aforementioned vehicle, When the aforementioned interference request signal is received, The interference signal is transmitted based on the status of the vehicle as determined. The communication network system according to claim 8.

11. The aforementioned interference request device is The aforementioned communication error situation is as follows: The communication device acquires information on the number of communication errors that occurred while it was transmitting data a predetermined number of times. The communication network system according to claim 8.

12. The aforementioned interference request device is The aforementioned communication error situation is as follows: The communication network system acquires information on the number of communication errors that occurred during a predetermined number of data transmissions. The communication network system according to claim 8.

13. The aforementioned interference request device is The interference request signal is transmitted when the number of communication errors obtained as part of the communication error status exceeds a predetermined value. A communication network system according to claim 11 or claim 12.

14. Default values ​​are set for each communication device. The aforementioned interference request device is The interference request signal is transmitted when the number of communication errors for any of the aforementioned communication devices exceeds the predetermined value. The communication network system according to claim 11.

15. The aforementioned jamming device is If the detected status of the vehicle indicates that it is operating autonomously, the interference signal will not be transmitted. A communication network system according to claim 3 or claim 10.

16. The aforementioned jamming device is If the vehicle's status is determined to be undergoing fault diagnosis, the interference signal will not be transmitted. A communication network system according to claim 3 or claim 10.

17. The aforementioned interference request device is If the detected status of the vehicle indicates that it is operating autonomously, the interference request signal will not be transmitted. The communication network system according to claim 9.

18. The aforementioned interference request device is If the vehicle's status is determined to be undergoing fault diagnosis, the interference request signal will not be transmitted. The communication network system according to claim 9.

19. This jamming device is applied to a communication network system comprising multiple communication devices and a management device that transmits start signals to the communication devices. The aforementioned multiple communication devices are, After sensing the aforementioned start signal, each communication device communicates with the others using a first communication method in which it transmits data in a predetermined order. If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the system is configured to switch to a second communication method that transmits data when no other communication device is transmitting data. Depending on the status of communication errors in the aforementioned communication network system, The communication device transmits an interfering signal that interferes with the detection of the start signal. jamming device.

20. A communication network system composed of multiple communication devices, The aforementioned communication network system is The system includes a management device that transmits a start signal to the aforementioned multiple communication devices, The aforementioned multiple communication devices are, After sensing the aforementioned start signal, each communication device communicates with the others using a first communication method in which it transmits data in a predetermined order. The aforementioned control device is Depending on the communication error status in the aforementioned communication network system, the transmission of the start signal is stopped. The aforementioned multiple communication devices are, If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the communication method is switched to a second communication method in which data is transmitted when no other communication device is transmitting data. Communication network system.

21. The aforementioned control device is The status of the communication error in the aforementioned communication network system is acquired. Based on the acquired communication error status, the transmission of the start signal is stopped. The communication network system according to claim 20.

22. The aforementioned communication network system is installed in the vehicle. The aforementioned control device is Assess the status of the aforementioned vehicle, Based on the acquired communication error status and the assessed vehicle status, the transmission of the start signal is stopped. The communication network system according to claim 21.

23. The aforementioned control device is The aforementioned communication error situation is as follows: The communication device acquires information on the number of communication errors that occurred while it was transmitting data a predetermined number of times. The communication network system according to claim 21.

24. The aforementioned control device is The aforementioned communication error situation is as follows: The communication network system acquires information on the number of communication errors that occurred during a predetermined number of data transmissions. The communication network system according to claim 21.

25. The aforementioned control device is If the number of communication errors obtained as a result of the aforementioned communication error status exceeds a predetermined value, the transmission of the start signal is stopped. A communication network system according to claim 23 or claim 24.

26. Default values ​​are set for each communication device. The aforementioned control device is The transmission of the start signal is stopped if the number of communication errors for any of the aforementioned communication devices exceeds the predetermined value. The communication network system according to claim 23.

27. The aforementioned communication network system is The system includes a stop request device that transmits a stop request signal to the management device requesting it to stop transmitting the start signal, The stop request device is, The status of the communication error in the aforementioned communication network system is acquired. Based on the acquired communication error status, the stop request signal is transmitted. The aforementioned control device is When the stop request signal is received, the transmission of the start signal is stopped. The communication network system according to claim 20.

28. The aforementioned communication network system is installed in the vehicle. The stop request device is, Assess the status of the aforementioned vehicle, The stop request signal is transmitted based on the acquired communication error status and the assessed vehicle status. The communication network system according to claim 27.

29. The aforementioned communication network system is installed in the vehicle. The aforementioned control device is Assess the status of the aforementioned vehicle, When the aforementioned stop request signal is received, The transmission of the start signal is stopped based on the status of the vehicle as determined. The communication network system according to claim 27.

30. The stop request device is, The aforementioned communication error situation is as follows: The communication device acquires information on the number of communication errors that occurred while it was transmitting data a predetermined number of times. The communication network system according to claim 27.

31. The stop request device is, The aforementioned communication error situation is as follows: The communication network system acquires information on the number of communication errors that occurred during a predetermined number of data transmissions. The communication network system according to claim 27.

32. The stop request device is, The stop request signal is transmitted when the number of communication errors obtained as part of the communication error status exceeds a predetermined value. A communication network system according to claim 30 or claim 31.

33. Default values ​​are set for each communication device. The stop request device is, The stop request signal is transmitted when the number of communication errors for any of the aforementioned communication devices exceeds the predetermined value. The communication network system according to claim 30.

34. The aforementioned control device is If the detected status of the vehicle indicates that it is in autonomous driving mode, the transmission of the start signal will not be stopped. A communication network system according to claim 22 or claim 29.

35. The aforementioned control device is If the vehicle's status is determined to be undergoing fault diagnosis, the transmission of the start signal will not be stopped. A communication network system according to claim 22 or claim 29.

36. The stop request device is, If the detected status of the vehicle indicates that it is operating autonomously, the stop request signal will not be transmitted. The communication network system according to claim 28.

37. The stop request device is, If the vehicle's status is determined to be undergoing fault diagnosis, the stop request signal will not be transmitted. The communication network system according to claim 28.

38. A management device that transmits a start signal in a communication network system composed of multiple communication devices. The aforementioned multiple communication devices are, After sensing the aforementioned start signal, each communication device communicates with the others using a first communication method in which it transmits data in a predetermined order. If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the system is configured to switch to a second communication method that transmits data when no other communication device is transmitting data. Depending on the status of communication errors in the aforementioned communication network system, Stop transmitting the aforementioned start signal. Management device.

39. The aforementioned communication device is When switching the communication method from the first communication method to the second communication method, If there is data to be transmitted immediately after switching to the second communication method, Set an offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data. When the set offset time has elapsed, the transmission of the data will begin. A communication network system according to claim 1 or claim 20.

40. The aforementioned communication device is When switching the communication method from the first communication method to the second communication method, If there is data to be transmitted immediately after switching to the second communication method, The offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data is set to become shorter as the size of the data to be transmitted increases. When the set offset time has elapsed, the transmission of the data will begin. A communication network system according to claim 1 or claim 20.

41. Each of the aforementioned communication devices is Priorities have been set in advance. The aforementioned communication device is When switching the communication method from the first communication method to the second communication method, If there is data to be transmitted immediately after switching to the second communication method, The offset time from the moment the communication method is switched to the second communication method until the start of transmission of the data is set to be shorter for higher priority, When the set offset time has elapsed, the transmission of the data will begin. A communication network system according to claim 1 or claim 20.

42. A vehicle equipped with the communication network system described in claim 1.

43. A vehicle equipped with the communication network system described in claim 20.

44. This program is applied to jamming devices for communication network systems. The aforementioned communication network system is It comprises multiple communication devices and a management device that transmits a start signal, The aforementioned multiple communication devices are, After sensing the aforementioned start signal, they communicate with each other using a first communication method that transmits each data in a predetermined order. If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the system is configured to switch to a second communication method that transmits data when no other communication device is transmitting data. Based on the communication error status in the aforementioned communication network system, The jamming device is instructed to transmit a jamming signal that interferes with the communication device's detection of the start signal. program.

45. This program is applied to a management device that transmits a start signal in a communication network system composed of multiple communication devices. The aforementioned multiple communication devices are, After sensing the aforementioned start signal, they communicate with each other using a first communication method that transmits each data in a predetermined order. If the state in which the start signal is not detected continues for a predetermined period of time, Regardless of the predetermined order, the system is configured to switch to a second communication method that transmits data when no other communication device is transmitting data. Based on the communication error status in the aforementioned communication network system, The control device is instructed to stop transmitting the start signal. program.

46. It consists of multiple communication devices, A control device that transmits a start signal, The system includes a jamming device that transmits a jamming signal that interferes with the detection of the start signal by the communication device, The aforementioned multiple communication devices This is a communication method in a communication network system that communicates with each other using a first communication method that transmits each data in a predetermined order after sensing the aforementioned start signal. The interference device transmits the interference signal based on the status of communication errors in the communication network system. The steps include: switching the communication method to a second communication method in which, if the plurality of communication devices fail to detect the start signal for a predetermined period of time, the device transmits data when no other communication device is transmitting data, regardless of the predetermined order; including Communication method.

47. It consists of multiple communication devices, Equipped with a control device that transmits a start signal, The aforementioned multiple communication devices This is a communication method in a communication network system that communicates with each other using a first communication method that transmits each data in a predetermined order after sensing the aforementioned start signal. The management device stops transmitting the start signal based on the status of communication errors in the communication network system, The steps include: switching the communication method to a second communication method in which, if the plurality of communication devices fail to detect the start signal for a predetermined period of time, the device transmits data when no other communication device is transmitting data, regardless of the predetermined order; including Communication method.

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