Correction device, communication system, and correction method

Abstract

To provide a technique capable of optimizing communication quality of a communication network.SOLUTION: In S103, the determination unit 55 determines, based on at least time information included in a frame received by the second communication device from the first communication device via at least one relay device, whether or not correction is necessary for a communication parameter among settings for transmitting a frame set in at least one target device. In S104 and S105, when the determination unit 55 determines that the communication parameter needs to be corrected, the correction notifying unit 56 adjusts the communication parameter so as to suppress a decrease in communication qualities and notifies at least one target device of a new communication parameter.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a correction device, a communication system, and a correction method. [Background technology]

[0002] Patent Document 1 below proposes a technology for correcting the timing at which a communication device transmits data in a communication network. Specifically, if the difference between the timing at which a relay device actually receives data from a communication device and the timing at which the communication device transmits data scheduled in advance is equal to or greater than a predetermined threshold, the relay device transmits a correction request to the communication device to correct the timing at which the communication device transmits data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-47163 Summary of the Invention [Problem to be solved by the invention]

[0004] However, after detailed investigation by the inventors, it was found that the technology of Patent Document 1 only corrects the timing at which the communication device transmits data, and does not take into consideration corrections to optimize the communication quality of the communication network.

[0005] One aspect of the present disclosure provides a technique that can optimize communication quality in a communication network. [Means for solving the problem]

[0006] One aspect of the present disclosure is a correction device (6) used in a communication system (100) in which multiple communication devices (1-4) are communicatively connected via at least one relay device (5). At least one of the multiple communication devices includes a first communication device (1-3), and at least one of the multiple communication devices other than the first communication device includes a second communication device (4). The correction device is a communication device. The first communication device and / or at least one relay device is at least one target device. The at least one target device communicates according to communication parameters, which are parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46). The correction device includes a determination unit (55, S103) and a correction notification unit (56, S104, S105). The determination unit is configured to determine whether or not communication parameters of settings for transmitting a frame set in at least one target device need to be corrected, based on at least time information included in the frame received by the second communication device from the first communication device via at least one relay device. The correction notification unit is configured, when the determination unit determines that the communication parameters need to be corrected, to adjust the communication parameters so as to suppress deterioration of communication quality and notify the at least one target device of the new communication parameters.

[0007] According to this configuration, the correction device aggregates at least time information included in frames received by the second communication device from the first communication device via at least one relay device. Therefore, the correction device can adjust communication parameters using the aggregated information to optimize the entire communication network. Furthermore, when new communication parameters are notified from the correction device, at least one target device corrects its communication parameters. Therefore, the communication parameters can be reset. In other words, the correction device can automatically optimize the communication network and correct the communication parameters. Therefore, the correction device can optimize the communication quality of the communication network.

[0008] One aspect of the present disclosure may be a communication system (100) and a correction method. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a communication system. [Figure 2] FIG. 1 is a block diagram showing a configuration of a communication system. [Figure 3] 10 is a flowchart illustrating a correction notification process. [Figure 4] Fig. 4A is an example of a graph when there is a bias in the amount of communication data per unit time, and Fig. 4B is an example of a graph when there is little bias in the amount of communication data per unit time. [Figure 5] Fig. 5A is a diagram illustrating an example of the timing at which data A, B, and C are transmitted. Fig. 5B is a diagram illustrating an example of the timing at which data A, B, and C are received. [Figure 6] FIG. 10 is a diagram illustrating an example of a schematic configuration of a communication system according to a first modification. [Figure 7] FIG. 10 is a diagram illustrating an example of a schematic configuration of a communication system according to a second modification. [Figure 8] FIG. 11 is a block diagram showing the configuration of a communication system according to a third modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. First embodiment] [1-1.Configuration] The communication system 100 of the embodiment shown in FIGS. 1 and 2 constitutes an Ethernet (registered trademark) network system mounted on a vehicle such as a passenger car. More specifically, the communication system 100 is capable of performing network communication using functions provided by Ethernet TSN. Note that the network system constituted by the communication system 100 is not limited to Ethernet, and any network using any communication protocol may be used. The any communication protocol may include LIN, CAN, FlexRay (registered trademark), MOST (registered trademark), and CXPI (registered trademark). TSN is an abbreviation for "Time-Sensitive Networking." LIN is an abbreviation for "Local Interconnect Network." CAN is an abbreviation for "Controller Area Network." MOST is an abbreviation for "Media Oriented Systems Transport." CXPI is an abbreviation for "Clock Extension Peripheral Interface."

[0011] The communication system 100 includes a plurality of electronic control devices, ECU1, ECU2, ECU3, and ECU4 (hereinafter referred to as ECU1-4), a relay device 5, and a correction device 6. These are connected by communication lines. Specifically, each of ECU1-4 is connected to the relay device 5 via a communication line. Furthermore, the correction device 6 is connected to ECU1-4 and the relay device 5 via a communication line. Note that ECU is an abbreviation for "Electronic Control Unit." Furthermore, although ECU2 is omitted in FIG. 2, ECU2 has the same configuration as ECU1, and the description of ECU1 described below also applies to ECU2.

[0012] Sensors, actuators, etc. (not shown) are connected to the ECUs 1 to 4. The ECUs 1 to 4, for example, realize a function of transmitting data (e.g., frames) obtained from the sensors to the other ECUs 1 to 4 via the relay device 5. Furthermore, for example, the ECUs 1 to 4 realize a function of operating actuators based on data received from the other ECUs 1 to 4 via the relay device 5. Furthermore, the ECUs 1 to 4 have a function of transmitting and receiving data to and from the relay device 5 to which they are connected.

[0013] That is, in the communication system 100, the ECUs 1 to 4 are connected to each other so as to be able to communicate with each other via the relay device 5. In other words, the ECUs 1 to 4 are configured so as to be able to transmit and receive data to and from each other via the relay device 5. Hereinafter, as an example, this embodiment will be described using a situation in which the ECUs 1 to 3 function as transmitting devices that transmit data, and the ECU 4 functions as a receiving device that receives data. As an example, as shown in FIG. 1, the ECU 1 transmits data A, the ECU 2 transmits data B, and the ECU 3 transmits data C. Note that the ECUs 1 to 3 may also be referred to as transmitting devices, and the ECU 4 as a receiving device. The ECUs 1 to 4, the relay device 5, and the correction device 6 may also be referred to as nodes.

[0014] [1-1-1.Transmitting device] 2, the ECU 1 includes a CPU 11 and a memory 12. The memory 12 stores a program for the CPU 11 to execute a predetermined function. The memory 12 also stores a first transmission setting, which is a setting for transmitting frames. The first transmission setting includes parameters such as a frame transmission period, a frame transmission timing offset, a frame priority, an Ethernet TSN setting, a frame format, and source and destination MAC addresses.

[0015] The frame transmission timing offset is a setting value for changing the frame transmission timing from the reference timing for frame transmission. For example, even if nodes have the same transmission period, changing the offset can shift the frame transmission timing.

[0016] For example, the frame priority is determined by the PCP value of the VLAN tag defined in IEEE802.1Q. IEEE stands for "Institute of Electrical and Electronics Engineers." VLAN stands for "Virtual Local Area Network." PCP stands for "Priority Code Point."

[0017] The Ethernet TSN settings are settings for functions defined in, for example, IEEE802.1Qav, IEEE802.1Qcr, IEEE802.1Qbv, etc. More specifically, settings for time slots and credit parameters allocated to each node are included.

[0018] Among the first transmission settings set in the transmitting device, parameters relating to communication quality are referred to as “first communication parameters.” The first communication parameters are rewritably recorded in the memory 12. The communication quality here refers to an index for evaluating the performance and configuration of the network that the communication system 100 constitutes. More specifically, it is an index for evaluating how efficiently frames are transmitted and received and how efficiently network resources are utilized. Specifically, the communication system 100 uses delay time, jitter, buffer capacity, processing load, etc. as indexes.

[0019] Delay time indicates the time it takes for a frame to reach its destination from its sender. If the delay time meets the required value for the communication system 100, the communication quality can be evaluated as good. Jitter indicates the fluctuation of the delay time. If the fluctuation range of the delay time meets the required value for the communication system 100, the communication quality can be evaluated as good.

[0020] The buffer, as an example, refers to a storage area for storing frames from when the relay device 5 receives the frames from the transmitting device until when it forwards them to the receiving device. If the buffer capacity is appropriate, the communication quality can be evaluated as good. An appropriate buffer capacity refers to a situation in which the buffer capacity is equal to or greater than a predetermined value, and there is very little need to discard frames in the buffer or newly received frames. If there is no need to discard frames in the buffer or newly received frames, all frames are forwarded, and the communication quality can be evaluated as good.

[0021] The processing load indicates, for example, the processing load of the CPU 41 of the relay device 5. Specifically, it indicates the processing load when executing switching processing using VLAN. If the processing load meets the required value for the communication system 100, the communication quality can be evaluated as good.

[0022] The first communication parameters include at least the frame transmission period, the frame transmission timing offset, and the frame priority among the parameters of the first transmission setting. Note that the first communication parameters may also include Ethernet TSN settings, etc.

[0023] The ECU 1 realizes the functions of the following units by the CPU 11 executing the programs in the memory 12. That is, the ECU 1 has the functions of a time synchronization unit 13, a transmission time setting unit 14, a transmission unit 15, a reception unit 16, and a control unit 17.

[0024] The time synchronization unit 13 is configured to synchronize time with other nodes that also have time synchronization units. For example, IEEE802.1AS is used for time synchronization. Specifically, the local time used in one node is synchronized with the global time used in the other nodes.

[0025] The transmission time setting unit 14 is configured to set the transmission time ST of the frame to the header of the frame, which may use a format defined in IEEE1722.

[0026] The transmitter 15 is configured to transmit frames to the receiver device. The transmitter 15 transmits the frames in accordance with a first transmission configuration. In other words, the transmitter 15 transmits the frames in accordance with at least a first communication parameter.

[0027] The receiving unit 16 is configured to receive new first communication parameters from the correction device 6. The receiving unit 16 is also configured to be able to receive frames from the other ECUs 2 to 4 via the relay device 5. The control unit 17 is configured to correct the first communication parameters to the new first communication parameters received by the receiving unit 16. That is, the control unit 17 is configured to correct the first communication parameters to the new first communication parameters notified by the correction device 6. Specifically, the control unit 17 updates the first communication parameters recorded in the memory 12 to the new first communication parameters. As a result, the next time the transmitting unit 15 transmits a frame, the transmitting unit 15 can transmit the frame to the receiving device in accordance with the new first transmission settings.

[0028] The ECU 3 includes a CPU 21 and a memory 22. The memory 22 stores a program for the CPU 21 to execute a predetermined function. The memory 22 also stores a first transmission setting. The memory 22 also stores a first communication parameter in a rewritable manner.

[0029] The ECU 3 realizes the functions of the following units by the CPU 21 executing the programs in the memory 22. That is, the ECU 3 has the functions of a transmitter 25, a receiver 26, and a controller 27. The ECU 3 differs from the ECUs 1 and 2 in that it does not have the time synchronizer 13 and the transmission time assigner 14.

[0030] The transmitting unit 25 is configured to transmit a frame to a receiving device. The transmitting unit 25 transmits the frame in accordance with the first transmission setting. However, since the ECU 3 does not include the time synchronization unit 13 and the transmission time setting unit 14, the header of the frame transmitted from the ECU 3 does not include the transmission time ST of the frame. The receiving unit 26 and the control unit 27 have the same configuration as the receiving unit 16 and the control unit 17 of the ECU 1. The receiving unit 26 is also configured to be able to receive frames from the other ECUs 1, 2, and 4 via the relay device 5.

[0031] [1-1-2. Receiving device] The ECU 4 includes a CPU 31 and a memory 32. The memory 32 stores programs that enable the CPU 31 to execute predetermined functions.

[0032] The ECU 4 realizes the functions of the following units by the CPU 31 executing the programs in the memory 32. That is, the ECU 4 has the functions of a time synchronization unit 33, a receiving unit 34, a storage unit 35, and a notification unit 36.

[0033] The time synchronization unit 33 is configured to synchronize the time with other nodes that also have time synchronization units. The receiving unit 34 is configured to receive the frame transmitted from the transmitting device via the relay device 5.

[0034] The memory unit 35 is a storage device for storing notification information. The notification information is information related to a frame transmitted by a transmitting device. In other words, the notification information is traffic information from when the frame transmitted by the transmitting device is received by the receiving device. The notification information includes at least time information. More specifically, the notification information includes a transmission time ST, which is the time when the transmitting device transmits the frame, a reception time, which is the time when the receiving device receives the frame, the frame size, the frame priority, the sender address, etc.

[0035] The notification unit 36 ​​is configured to notify the correction device 6 of the notification information stored in the storage unit 35. More specifically, the notification unit 36 ​​is configured to periodically collectively notify the correction device 6 of the notification information stored in the storage unit 35. Note that the notification unit 36 ​​may notify the correction device 6 of the notification information each time it receives a frame transmitted from the ECUs 1 to 3.

[0036] [1-1-3.Relay device] The relay device 5 has a relay function of transferring a frame received from an ECU connected to the relay device 5 to another ECU connected to the relay device 5. That is, in this embodiment, the relay device 5 relays communications between ECUs 1 to 4. The relay device 5 may also have a function as a gateway device. By having the function as a gateway device, the relay device 5 can relay frames (data) between different communication protocols. The relay device 5 also has a function of relaying frames between different VLANs.

[0037] The relay device 5 functions as a microcomputer including a CPU 41 and a memory 42. The memory 42 stores a program for the CPU 41 to execute a predetermined function. The memory 42 also stores second transmission settings, which are settings for transmitting (in other words, relaying) frames. The second transmission settings include parameters such as a forwarding table, an access control list, and Ethernet TSN settings. Of the second transmission settings, parameters related to the above-mentioned communication quality are referred to as second communication parameters. The second communication parameters are rewritably stored in the memory 42.

[0038] The forwarding table is a data table that indicates forwarding paths. Specifically, the forwarding table is a data table that associates the MAC address of the frame sender with the MAC address of the forwarding destination.

[0039] The access control list is, for example, a list that sets conditions for frames that are allowed to pass through the relay device 5. Frames that meet the conditions are permitted to be transferred, and frames that do not meet the conditions are discarded.

[0040] The Ethernet TSN settings are settings for functions defined in, for example, IEEE802.1Qav, IEEE802.1Qcr, IEEE802.1Qbv, etc. More specifically, the Ethernet TSN settings include settings for output policing, etc.

[0041] The second communication parameters include at least Ethernet TSN settings among the parameters of the second transmission settings. The second communication parameters may also include a forwarding table, an access control list, and the like.

[0042] The relay device 5 realizes the functions of the following units by the CPU 41 executing the programs in the memory 42. That is, the relay device 5 has the functions of a time synchronization unit 43, a transfer unit 44, a receiving unit 45, and a control unit 46.

[0043] The time synchronization unit 43 is configured to synchronize the time with other nodes that also have time synchronization units. The transfer unit 44 is configured to transfer a frame received from the transmitting device to the receiving device. The transfer unit 44 also determines whether a transmission time ST is added to the header of the frame received from the transmitting device. If the transfer unit 44 determines that the transmission time ST is not added to the header of the frame, the transfer unit 44 is configured to add a relay reception time, which is the time when the relay device 5 received the frame, to the header of the frame as the transmission time ST when the transmitting device transmitted the frame.

[0044] The receiving unit 45 is configured to receive new second communication parameters from the correction device 6 . The control unit 46 is configured to correct the second communication parameters to the new second communication parameters received by the receiving unit 45. That is, the control unit 46 is configured to correct the second communication parameters to the new second communication parameters notified by the correction device 6. Specifically, the control unit 46 updates the second communication parameters recorded in the memory 42 to the new second communication parameters. As a result, the next time the transfer unit 44 transfers a frame, the transfer unit 44 can transfer the frame to the receiving device in accordance with the new second transmission settings.

[0045] [1-1-4. Correction device] The correction device 6 is a communication device for correcting the first communication parameter and the second communication parameter so as to optimize the communication quality of the communication network that the communication system 100 constitutes.

[0046] The correction device 6 includes a CPU 51 and a memory 52. ​​The memory 52 stores a program for the CPU 51 to execute a predetermined function. The memory 52 stores first communication parameters of each transmitting device and second communication parameters of the relay device 5 in a rewritable manner.

[0047] The correction device 6 realizes the functions of the following units by the CPU 51 executing the program in the memory 52. ​​That is, the relay device 5 has functions as a receiving unit 53, a storage unit 54, a determining unit 55, and a correction notifying unit 56.

[0048] The receiving unit 53 is configured to receive the notification information notified by the notifying unit 36 ​​of the receiving device. The storage unit 54 is a storage device for storing the notification information received by the receiving unit 53.

[0049] The determination unit 55 is configured to determine whether or not the first communication parameters and the second communication parameters need to be corrected based on at least the time information included in the notification information stored in the storage unit 54.

[0050] The correction notification unit 56 is configured to adjust the first and second communication parameters so as to suppress a deterioration in communication quality when the determination unit 55 determines that the first and second communication parameters need to be corrected. The correction notification unit 56 is also configured to notify the transmitting device and the relay device 5 of the new first and second communication parameters after adjustment. The first and second communication parameters stored in the memory 52 are also updated to the new first and second communication parameters after adjustment. The correction notification process performed by the determination unit 55 and the correction notification unit 56 will be described in detail later.

[0051] Each of the ECUs 1 to 4, the relay device 5, and the correction device 6 may include one microcomputer or multiple microcomputers. The method for realizing the functions of each unit included in the ECUs 1 to 4, the relay device 5, and the correction device 6 is not limited to software, and some or all of the functions may be realized using one or more pieces of hardware. For example, when the functions are realized by an electronic circuit that is hardware, the electronic circuit may be realized by a digital circuit, an analog circuit, or a combination of these.

[0052] [1-2. Processing] The correction notification process executed by the correction device 6 will be described with reference to the flowchart shown in Fig. 3. This correction notification process is repeatedly executed while the ignition switch is on. Hereinafter, the first communication parameters and / or the second communication parameters may also be referred to as notification parameters.

[0053] First, in S101, the receiving unit 53 of the correction device 6 receives notification information from the ECU 4. Subsequently, in S102, the correction device 6 stores the notification information received from the ECU 4 in the storage unit .

[0054] Next, in S103, the determination unit 55 of the correction device 6 determines whether or not the notification parameters need to be corrected based on the notification information. In this embodiment, the determination unit 55 determines whether or not the difference between each transmission time ST, which is the time when each of the ECUs 1 to 3 transmits a frame, and each reception time, which is the time when the ECU 4 receives each frame, is equal to or greater than a predetermined tolerance. That is, the determination unit 55 calculates a delay time from the difference between the transmission time ST and reception time of each frame, and determines whether or not the delay time is equal to or greater than the tolerance. If the determination unit 55 determines that the difference between the transmission time ST and the reception time is equal to or greater than the tolerance, it determines that the communication parameters need to be corrected.

[0055] If the correction device 6 determines in S103 that the communication parameters need to be corrected, the process proceeds to S104. On the other hand, if the correction device 6 determines in S103 that the communication parameters do not need to be corrected, the correction notification process ends.

[0056] In S104, the correction notification unit 56 of the correction device 6 adjusts the communication parameters to suppress degradation of communication quality. In this embodiment, the correction notification unit 56 adjusts the communication parameters so that the difference between the transmission time ST and the reception time falls within an allowable value. In other words, the correction notification unit 56 adjusts the communication parameters so that the delay time falls within an allowable value. More specifically, the correction notification unit 56 changes settings such as the transmission period, offset, and priority in the ECUs 1 to 3, and changes settings such as output policing in the relay device 5.

[0057] As an example, consider a case where the difference between the transmission time ST and the reception time for ECU1 is equal to or greater than a tolerance. If the priority of the frame from ECU1 is lower than the priority of the frames from ECU2 and ECU3, when the frames from ECU1 to ECU3 are accumulated in the buffer of relay device 5, the frames from ECU2 and ECU3, which have higher priorities, may be relayed first. Therefore, it is possible that the frame from ECU1 has been staying in the buffer of relay device 5 for a long time. Therefore, for example, the correction notification unit 56 may adjust the priority of the frame from ECU1 so that it is higher than the priority of the frames from ECU2 and ECU3. Alternatively, for example, the correction notification unit 56 may change the output policing in relay device 5 to adjust the relay device 5 so that the frame from ECU1 is preferentially transferred.

[0058] Also, for example, it is possible that the transmission timing of ECU1 conflicts with the transmission timings of ECU2 and ECU3, and that it takes time for relay device 5 to transfer the data to the receiving device. Therefore, for example, if ECU1 to ECU3 have the same transmission cycle, the offset of ECU1 may be adjusted to be different from the offsets of ECU2 and ECU3 so that the transmission timing of ECU1 does not conflict with the transmission timings of ECU2 and ECU3. Also, for example, correction notification unit 56 may adjust the transmission cycles of ECU1 to ECU3 so that they are different from each other.

[0059] Next, in S105, the correction notification unit 56 notifies the ECUs 1 to 3 and the relay device 5 of new communication parameters. For example, in the above-mentioned scenario, the correction notification unit 56 may notify the ECU 1 of the PCP value of the new VLAN tag. Also, for example, the correction notification unit 56 may notify the ECU 1 of a new transmission period or offset value. Also, for example, the correction notification unit 56 may notify the relay device 5 of a new output policing setting value.

[0060] Thereafter, the correction device 6 ends this correction notification process. Upon receiving the new communication parameters, the ECUs 1 to 3 and the relay device 5 correct the currently recorded communication parameters. Specifically, the transmitting device corrects the first communication parameters recorded in the memories 12 and 22 to the new first communication parameters. Furthermore, the relay device 5 corrects the second communication parameters recorded in the memory 42 to the new second communication parameters.

[0061] [1-3.Effects] According to the first embodiment described above in detail, the following effects can be obtained. (1a) In the above embodiment, when it is determined that the communication parameters need to be corrected, the correction notification unit 56 of the correction device 6 adjusts the communication parameters so as to suppress a decrease in communication quality.

[0062] Here, the first transmission setting of the transmitter and the second transmission setting of the relay device 5 are designed and verified to meet predetermined delay time and jitter requirements. However, in vehicles such as SDVs, where functions can be added or updated even after the vehicle is sold, software may be updated frequently. It is difficult to change and verify the network configuration every time the software is updated. SDV stands for "Software Defined Service."

[0063] However, with the above-described configuration, notification information is aggregated in the correction device 6. In other words, traffic information of the entire network is aggregated in the correction device 6, so the correction device 6 can adjust communication parameters to optimize the entire network. Therefore, even when software is updated, the transmitting device can correct the first communication parameters. Furthermore, the relay device 5 can correct the second communication parameters. In other words, in the communication system 100, the first transmission setting and the second transmission setting can be reconfigured without physically changing the network. In other words, in the communication system 100, the network can be automatically optimized and the communication parameters can be corrected. Therefore, in the communication system 100, the communication quality of the communication network can be optimized.

[0064] (1b) In the above embodiment, if the determination unit 55 of the correction device 6 determines that the difference between the sending time ST and the receiving time is equal to or greater than the allowable value, it determines that the communication parameters need to be corrected. Furthermore, the correction notification unit 56 of the correction device 6 adjusts the communication parameters so that the difference between the sending time ST and the receiving time falls within the allowable value. With this configuration, the delay time from the frame sender to the receiver can be kept within the allowable value. Therefore, the communication quality of the communication network can be optimized.

[0065] [1-4. Correspondence] In the first embodiment, S103 corresponds to the process of the determination unit, and S104 and S105 correspond to the process of the correction notification unit. Furthermore, ECUs 1 to 3 correspond to the first communication device, and ECU 4 corresponds to the second communication device. Furthermore, the first communication parameter and the second communication parameter correspond to the communication parameters.

[0066] [2. Second Embodiment] [2-1. Differences from the first embodiment] The second embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference will be made to the preceding description.

[0067] In the second embodiment, the specific process for determining whether or not the communication parameters need to be corrected is different in S103 of Fig. 3. Also, the specific process for adjusting the communication parameters so as to suppress a deterioration in communication quality is different in S104 of Fig. 3. Also, the specific values ​​of the communication parameters to be notified are different in S105 of Fig. 3.

[0068] [2-2. Processing] In S103, the determination unit 55 of the correction device 6 determines whether or not there is a bias in the amount of communication data per unit time, using the amount of communication data per unit time calculated based on the transmission times ST at which each of the ECUs 1 to 3 transmitted a frame and the size of each of the frames transmitted by each of the ECUs 1 to 3. If the determination unit 55 determines that there is a bias in the amount of communication data per unit time, it determines that the communication parameters need to be corrected. Note that the amount of communication data per unit time may be calculated in advance as statistical information before this correction notification process is executed.

[0069] More specifically, the determination unit 55 determines whether or not there are dense sections in which the amount of communication data per unit time is relatively large and sparse sections in which the amount of communication data per unit time is relatively small, using the amount of communication data per unit time. As shown in Fig. 4A, when the determination unit 55 determines that there are dense sections and sparse sections, it determines that the communication parameters need to be corrected.

[0070] Specifically, the determination unit 55 determines whether the amount of communication data exceeds an upper reference value H. If the determination unit 55 determines that the amount of communication data exceeds the upper reference value H, it determines that a dense section exists. Furthermore, the determination unit 55 determines whether the amount of communication data is below a lower reference value L. If the determination unit 55 determines that the amount of communication data is below the lower reference value L, it determines that a sparse section exists. The upper reference value H and the lower reference value L are predetermined reference values ​​for distinguishing between large and small amounts of communication data per unit time. The upper reference value H is a value greater than the lower reference value L.

[0071] In S104, the correction notification unit 56 of the correction device 6 adjusts the communication parameters to suppress imbalance in the amount of communication data per unit time. More specifically, the correction notification unit 56 adjusts the communication parameters so that an ECU, among ECUs 1 to 3, that has transmitted a frame to a dense section can transmit a frame to a sparse section. More specifically, the correction notification unit 56 changes settings such as the transmission period and offset in ECUs 1 to 3.

[0072] As an example, consider a case where ECU1 and ECU2 transmit frames in a dense section. For example, if the transmission cycles and offsets of the frames transmitted by ECU1 and ECU2 are the same, the correction notification unit 56 may adjust the offset of one of them. Alternatively, for example, the correction notification unit 56 may adjust the transmission cycles of ECU1 and ECU2 to be different.

[0073] In S105, for example, the correction notification unit 56 may notify the ECU1 or ECU2 of a new offset value. Also, for example, the correction notification unit 56 may notify the ECU1 and ECU2 of a new transmission period value.

[0074] [2-3. Effects] According to the second embodiment described above in detail, in addition to the effect (1a) of the first embodiment described above, the following effect can be obtained.

[0075] (2a) In the above embodiment, when the determination unit 55 determines that there is a bias in the amount of communication data per unit time, it determines that the communication parameters need to be corrected. Furthermore, the correction notification unit 56 adjusts the communication parameters so as to suppress the bias in the amount of communication data per unit time.

[0076] When there is a bias in the amount of communication data per unit time, it is considered that in a dense section, traffic is temporarily concentrated on the relay device 5. Therefore, there is a possibility that the buffer of the relay device 5 will overflow. This may result in frame delays or low-priority frames being discarded.

[0077] However, with the above-described configuration, traffic congestion can be resolved, thereby leveling out the traffic in the communication system 100 as shown in Fig. 4B. In other words, the amount of communication data per unit time is always kept between the upper reference value H and the lower reference value L. This makes it possible to prevent the buffer of the relay device 5 from overflowing. This makes it possible to optimize the communication quality of the communication network.

[0078] Furthermore, it is no longer necessary to adjust the buffer queue capacity of the relay device 5 to the amount of communication data in the dense section. Therefore, the buffer queue capacity of the relay device 5 can be reduced, allowing for efficient use of network resources.

[0079] Furthermore, when traffic density is high, it is possible that an excessive load is being placed on switching processing using VLANs. In this case, the processing load on the CPU 41 of the relay device 5 increases. However, with the above-described configuration, the traffic density can be reduced, thereby preventing the processing load on the CPU 41 of the relay device 5 from increasing. This allows for efficient use of network resources.

[0080] 3. Third Embodiment [3-1. Differences from the first embodiment] The third embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference will be made to the preceding description.

[0081] In the third embodiment, the specific process for determining whether or not the communication parameters need to be corrected is different in S103 of Fig. 3. Also, the specific process for adjusting the communication parameters so as to suppress a deterioration in communication quality is different in S104 of Fig. 3. Also, the specific values ​​of the communication parameters to be notified are different in S105 of Fig. 3.

[0082] [3-2. Processing] In the third embodiment, it is assumed that the ECU 4 integrates and uses the sensor data transmitted from the ECUs 1 to 3. That is, the data from each sensor is used as data in a so-called sensor-fused state. In such a case, it is preferable that the data from each sensor is sampled as close to each other as possible. Therefore, it is preferable that the data from each sensor is transmitted from the ECUs 1 to 3 as close to each other as possible and is received by the ECU 4 as close to each other as possible.

[0083] In S103, the determination unit 55 of the correction device 6 determines whether or not the difference between the first transmission time, which is the earliest time, and the second transmission time, which is the latest time, among the transmission times ST, which are the times when each of the ECUs 1 to 3 transmitted a frame, exceeds a predetermined threshold. The determination unit 55 also determines whether or not the difference between the first reception time, which is the earliest time, and the second reception time, which is the latest time, among the reception times, which are the times when the ECU 4 received each frame, exceeds a threshold. If the determination unit 55 determines that the difference between the first transmission time and the second transmission time exceeds the threshold and / or the difference between the first reception time and the second reception time exceeds the threshold, the determination unit 55 determines that the communication parameters need to be corrected.

[0084] For example, let us consider a case where ECU1 transmits data A, ECU2 transmits data B, and ECU3 transmits data C as a frame. Data A corresponds to a frame transmitted at a first transmission time and a frame received at a first reception time. Data C corresponds to a frame transmitted at a second transmission time and a frame received at a second reception time. The threshold is set to 30 ms. As shown in FIG. 5A, the difference between the first transmission time and the second transmission time is 30 ms, which does not exceed the threshold. However, as shown in FIG. 5B, the difference between the first reception time and the second reception time is 50 ms, which exceeds the threshold. In this case, since the difference between the first reception time and the second reception time exceeds the threshold, the determination unit 55 determines that the communication parameters need to be corrected.

[0085] In S104, the correction notification unit 56 adjusts the communication parameters so that the difference between the first transmission time and the second transmission time falls within a threshold value, and so that the difference between the first reception time and the second reception time falls within a threshold value.

[0086] In this embodiment, the correction notification unit 56 adjusts the time so that the remaining two pieces of data A, B, and C are transmitted within a threshold after the first piece of data is transmitted. Also, the correction notification unit 56 adjusts the time so that the remaining two pieces of data A, B, and C are received within a threshold after the first piece of data is received.

[0087] For example, if the priority of a frame from a transmitting device that received a frame latest among multiple transmitting devices is lower than the priority of frames from the other transmitting devices, the correction notification unit 56 may adjust the priority of the frame from the transmitting device that received a frame latest among the multiple transmitting devices to be higher than the current priority. Specifically, the correction notification unit 56 may adjust the priority of data C, which is the data that was received latest, to be higher than the current priority. This is thought to shorten the time that data C remains in the buffer of relay device 5.

[0088] Furthermore, for example, the correction notification unit 56 may adjust the setting of output policing in the relay device 5. Specifically, the adjustment may be made so that frames of data C are transferred with priority. Furthermore, if the difference between the first transmission time and the second transmission time exceeds a threshold, it is possible that the transmission cycles and offsets of the multiple transmission devices are misaligned. Therefore, for example, the transmission cycles and offsets of the multiple transmission devices may be adjusted to match. Specifically, the correction notification unit 56 may adjust the transmission cycles and offsets of data A, B, and C to match each other.

[0089] In S105, for example, the correction notification unit 56 may notify the ECU 3 of the PCP value of the new VLAN tag. Also, for example, the correction notification unit 56 may notify the relay device 5 of a new output policing setting value. Also, for example, the correction notification unit 56 may notify the ECUs 1 to 3 of new transmission cycle and offset values.

[0090] [3-3. Effects] According to the third embodiment described above in detail, in addition to the effect (1a) of the first embodiment described above, the following effect can be obtained.

[0091] (3a) In the above embodiment, when the determination unit 55 determines that the difference between the first transmission time and the second transmission time exceeds a threshold value and / or the difference between the first reception time and the second reception time exceeds a threshold value, the determination unit 55 determines that the communication parameters need to be corrected. Furthermore, the correction notification unit 56 adjusts the communication parameters so that the difference between the first transmission time and the second transmission time falls within the threshold value, and so that the difference between the first reception time and the second reception time falls within the threshold value. This configuration can reduce the variation in the delay time of each frame. In other words, it can improve the jitter of each frame. Therefore, the communication system 100 can optimize the communication quality of the communication network.

[0092] Furthermore, the receiving device can use data sampled at similar times, which allows the receiving device to use data suitable for processing that requires real-time performance or high response speed.

[0093] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0094] (4a) In the above embodiment, the communication system 100 constitutes an in-vehicle network mounted on a vehicle. However, the type of network constituted by the communication system 100 is not limited to this. For example, the communication system 100 may constitute a wide area network or an industrial network.

[0095] (4b) In the above embodiment, the communication system 100 includes one relay device 5. However, as shown in Modification 1 of FIG. 6, the communication system 100 may include multiple relay devices 5. The correction device 6 may notify the multiple relay devices 5 of new second communication parameters.

[0096] (4c) In the above embodiment, the ECUs 1 to 3 are connected in parallel to the relay device 5. However, the manner in which the transmitter is connected to the relay device 5 is not limited to this. For example, as shown in Modification 2 of FIG. 7, the transmitter may be connected to the relay device 5 in a multi-drop connection. The ECU 7 has the same configuration as any of the ECUs 1 to 3.

[0097] (4d) In the above embodiment, the ECU 4 (in other words, the receiving device) and the relay device 5 are separate entities. However, as shown in Modification 3 of FIG. 8 , the ECU 104 may have the functions of the receiving device and the correction device 6. Specifically, the ECU 104, which is the receiving device, may have the determination unit 55 and the correction notification unit 56. Alternatively, the ECU 104 may not have the notification unit 36, and the determination unit 55 may determine whether or not the first communication parameters and the second communication parameters require correction based on the notification information stored in the memory unit 35.

[0098] (4e) In the correction notification process, the processes of S103 to S105 in the first embodiment, the processes of S103 to S105 in the second embodiment, and the processes of S103 to S105 in the third embodiment may be executed in combination.

[0099] (4f) In the correction notification process, for example, the correction notification unit 56 may adjust to set a new time slot in S104, and notify the transmitting device of the new Ethernet TSN setting as a first communication parameter in S105. Also, for example, the correction notification unit 56 may adjust to set a new forwarding path in S104, and notify the relay device 5 of the new forwarding table as a second communication parameter in S105. Also, for example, the correction notification unit 56 may adjust the conditions for frames to be passed through the relay device 5 in S104, and notify the relay device 5 of the new access control list as a second communication parameter in S105.

[0100] (4g) Each device described in this disclosure (i.e., ECUs 1 to 4, relay device 5, correction device 6) and the method implemented by each device may be implemented by a dedicated computer configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, each device described in this disclosure and the method implemented by each device may be implemented by a dedicated computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, each device described in this disclosure and the method implemented by each device may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, a computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer. The method for implementing the functions of each unit included in each device does not necessarily need to include software; all of the functions may be implemented using one or more hardware.

[0101] (4h) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0102] (4i) In addition to the communication system 100 described above, the present disclosure can also be realized in various forms, such as each device that constitutes the communication system 100, a program for causing a computer to function as each device, a non-transient physical recording medium such as a semiconductor memory on which the program is recorded, and a correction method.

[0103] [Technical idea disclosed in this specification] [Item 1] A correction device (6) used in a communication system (100) in which a plurality of communication devices (1 to 4) are communicatively connected via at least one relay device (5), At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4), the correction device is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); a determination unit (55, S103) configured to determine whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected, based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device; a correction notification unit (56, S104, S105) configured, when the determination unit determines that the communication parameters need to be corrected, to adjust the communication parameters so as to suppress a deterioration in communication quality and notify the at least one target device of the new communication parameters; A correction device comprising:

[0104] [Item 2] The correction device according to item 1, the determination unit determines whether a difference between a transmission time, which is a time when the first communication device transmits the frame, and a reception time, which is a time when the second communication device receives the frame, is equal to or greater than a predetermined tolerance, and when it determines that the difference between the transmission time and the reception time is equal to or greater than the tolerance, determines that the communication parameters need to be corrected; The correction notification unit notifies the at least one target device of the communication parameters adjusted so that the difference between the transmission time and the reception time falls within the tolerance.

[0105] [Item 3] The correction device according to item 1 or 2, the at least one communication device includes a plurality of first communication devices; the determination unit determines whether or not there is a bias in the amount of communication data per unit time, using the amount of communication data per unit time calculated based on each transmission time, which is a time when each of the plurality of first communication devices transmitted the frame, and each size of the frame transmitted by each of the plurality of first communication devices; and when it is determined that there is a bias in the amount of communication data per unit time, determines that the communication parameters need to be corrected; The correction notification unit notifies the at least one target device of the communication parameters adjusted to suppress bias in the amount of communication data per unit time.

[0106] [Item 4] The correction device according to any one of items 1 to 3, the at least one communication device includes a plurality of first communication devices; the determination unit determines whether or not a difference between a first transmission time, which is the earliest time among the transmission times at which each of the plurality of first communication devices transmitted the frame, and a second transmission time, which is the latest time, exceeds a predetermined threshold, and whether or not a difference between a first reception time, which is the earliest time among the reception times at which each of the plurality of first communication devices received the frame, and a second reception time, which is the latest time, exceeds the threshold, and determines that the communication parameters need to be corrected when it is determined that the difference between the first transmission time and the second transmission time exceeds the threshold and / or the difference between the first reception time and the second reception time exceeds the threshold; The correction notification unit notifies the at least one target device of the communication parameters that have been adjusted so that the difference between the first transmission time and the second transmission time falls within the threshold value and so that the difference between the first reception time and the second reception time falls within the threshold value.

[0107] [Item 5] A communication system (100) in which a plurality of communication devices (1 to 4) are communicably connected via at least one relay device (5), At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4), The communication system includes a correction device (6) that is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); The correction device a determination unit (55, S103) configured to determine whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected, based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device; a correction notification unit (56, S104, S105) configured, when the determination unit determines that the communication parameters need to be corrected, to adjust the communication parameters so as to suppress a deterioration in communication quality and notify the at least one target device of the new communication parameters; A communication system comprising:

[0108] [Item 6] A correction method implemented by a correction device (6) used in a communication system (100) in which a plurality of communication devices (1 to 4) are communicatively connected via at least one relay device (5), comprising: At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4), the correction device is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); determining whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device (55, S103); If it is determined that the communication parameters need to be corrected, the communication parameters are adjusted so as to suppress deterioration of communication quality, and new communication parameters are notified to the at least one target device (56, S104, S105). A correction method comprising: [Explanation of symbols]

[0109] 1 to 4...ECU, 5...relay device, 6...correction device, 55...determination unit, 56...correction notification unit, 100...communication system.

Claims

1. A correction device (6) used in a communication system (100) in which a plurality of communication devices (1 to 4) are communicatively connected via at least one relay device (5), At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4); the correction device is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); a determination unit (55, S103) configured to determine whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected, based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device; and a correction notification unit (56, S104, S105) configured, when the determination unit determines that the communication parameters need to be corrected, to adjust the communication parameters so as to suppress a deterioration in communication quality and notify the at least one target device of the new communication parameters; A correction device comprising:

2. 2. The correction device according to claim 1, the determination unit determines whether a difference between a transmission time, which is a time when the first communication device transmits the frame, and a reception time, which is a time when the second communication device receives the frame, is equal to or greater than a predetermined tolerance, and when it determines that the difference between the transmission time and the reception time is equal to or greater than the tolerance, determines that the communication parameters need to be corrected; The correction notification unit notifies the at least one target device of the communication parameters adjusted so that the difference between the sending time and the receiving time falls within the tolerance.

3. 3. The correction device according to claim 1 or 2, the at least one communication device includes a plurality of first communication devices; the determination unit determines whether or not there is a bias in the amount of communication data per unit time, using the amount of communication data per unit time calculated based on each transmission time, which is the time when each of the plurality of first communication devices transmitted the frame, and each size of the frame transmitted by each of the plurality of first communication devices; and when it is determined that there is a bias in the amount of communication data per unit time, determines that the communication parameters need to be corrected; The correction notification unit notifies the at least one target device of the communication parameters adjusted to suppress bias in the amount of communication data per unit time.

4. 3. The correction device according to claim 1 or 2, the at least one communication device includes a plurality of first communication devices; the determination unit determines whether or not a difference between a first transmission time, which is the earliest time among the transmission times, which are times when each of the plurality of first communication devices transmitted the frame, and a second transmission time, which is the latest time, exceeds a predetermined threshold, and whether or not a difference between a first reception time, which is the earliest time among the reception times, which are times when each of the plurality of first communication devices received the frame, and a second reception time, which is the latest time, exceeds the threshold, and determines that the communication parameters need to be corrected when it is determined that the difference between the first transmission time and the second transmission time exceeds the threshold and / or the difference between the first reception time and the second reception time exceeds the threshold; The correction notification unit notifies the at least one target device of the communication parameters that have been adjusted so that the difference between the first transmission time and the second transmission time falls within the threshold value and so that the difference between the first reception time and the second reception time falls within the threshold value.

5. A communication system (100) in which a plurality of communication devices (1 to 4) are communicatively connected via at least one relay device (5), At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4); The communication system includes a correction device (6) that is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); The correction device a determination unit (55, S103) configured to determine whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected, based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device; and a correction notification unit (56, S104, S105) configured, when the determination unit determines that the communication parameters need to be corrected, to adjust the communication parameters so as to suppress a deterioration in communication quality and notify the at least one target device of the new communication parameters; A communication system comprising:

6. A correction method implemented by a correction device (6) used in a communication system (100) in which a plurality of communication devices (1 to 4) are communicatively connected via at least one relay device (5), comprising: At least one communication device among the plurality of communication devices includes a first communication device (1-3), and at least one communication device among the plurality of communication devices other than the first communication device includes a second communication device (4); the correction device is a communication device, The first communication device and / or the at least one relay device are at least one target device; the at least one target device communicates in accordance with communication parameters that are at least parameters related to communication quality, and corrects the communication parameters when notified of new communication parameters by the correction device (17, 27, 46); determining whether or not the communication parameters of the settings for transmitting the frame set in the at least one target device need to be corrected based on at least time information included in the frame received by the second communication device from the first communication device via the at least one relay device (55, S103); If it is determined that the communication parameters need to be corrected, the communication parameters are adjusted so as to suppress deterioration of communication quality, and new communication parameters are notified to the at least one target device (56, S104, S105). A correction method comprising:

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