Communication device, relay device, and communication method

Abstract

To provide a communication device, a relay device, and a communication method that calculate an entire period from when data transmission is instructed to when data determination is made.SOLUTION: A communication device transmits data to a relay device that transmits the received data. The communication device includes a processing unit that performs processing. The processing unit instructs transmission of data to the relay device, and obtains a transmission delay time from when the data transmission is instructed to when the data is transmitted. The processing unit obtains a determination delay time from when the relay device receives the data to a determination time point when it is determined whether to transmit the received data. The processing unit calculates an entire period from when the data transmission is instructed to the determination time point based on the obtained transmission delay time and determination delay time.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] Patent Document 1 discloses a communication system in which a communication device transmits data to another communication device via a relay device. The communication device transmits prioritized data that needs to reach another communication device within a short period of time. When the relay device receives prioritized data from the communication device, it determines whether or not to transmit the received prioritized data. An allowed period during which the transmission of prioritized data is permitted and a prohibited period during which the transmission of prioritized data is prohibited are set alternately and repeatedly. When the time point at which the relay device determines whether or not to transmit the prioritized data falls within the allowed period, it transmits the received prioritized data during the allowed period.

[0003] The total duration of the permitted period and the prohibited period is constant. The permitted period and the prohibited period constitute one cycle. If there is prioritized data whose determination time falls within the prohibited period, the relay device adjusts the start time or length of the permitted period. In this way, the relay device reduces the number of prioritized data whose determination time falls within the prohibited period. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 136843 Summary of the Invention [Problem to be solved by the invention]

[0005] When the communication device is able to calculate the entire period from when the data transmission is instructed to the time when the data is judged, for example, the communication device can adjust the time when the transmission of the prioritized data is instructed so that the judgment time of the prioritized data belongs to the permitted period. In this case, since the permitted period and the prohibited period can be fixed, it is not necessary to repeatedly adjust the permitted period.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a communication device, a relay device, and a communication method that calculates the entire period from when data transmission is instructed to the time when the data is judged. [Means for solving the problem]

[0007] A communication device according to one aspect of the present disclosure is a communication device that transmits data to a relay device that transmits the received data, and is equipped with a processing unit that executes processing, wherein the processing unit instructs the relay device to transmit data, obtains a transmission delay time from the instructing the relay device to transmit the data to the time the data is transmitted, obtains a judgment delay time from the time the relay device receives the data to a judgment point at which it is determined whether or not to transmit the received data, and calculates the overall period from the instructing the relay device to transmit data to the judgment point based on the obtained transmission delay time and judgment delay time.

[0008] A relay device according to one embodiment of the present disclosure is a relay device that transmits data received from a communication device, and is equipped with a receiving unit that receives data from the communication device and a processing unit that performs processing, and when the receiving unit receives data, the processing unit determines whether or not the receiving unit will transmit the received data, obtains a transmission delay time from when the communication device is instructed to transmit the data to when the data is transmitted, obtains a judgment delay time from when the receiving unit receives the data to a judgment point at which it is determined whether or not to transmit the received data, and calculates the entire period from when the communication device is instructed to transmit the data to the judgment point based on the obtained transmission delay time and judgment delay time.

[0009] A communication method according to one aspect of the present disclosure is a communication method for communicating data, in which a computer executes the steps of acquiring a transmission delay time from when a communication device instructs a relay device to transmit the received data to when the data is transmitted, acquiring a determination delay time from when the relay device receives the data to a determination time at which it is determined whether or not to transmit the received data, and calculating an overall period from when a data transmission is instructed to the determination time based on the acquired transmission delay time and determination delay time.

[0010] The present disclosure can be realized not only as a communication device or relay device having such a characteristic processing unit, but also as a communication method having such characteristic processing steps, or as a computer program for causing a computer to execute such steps. Furthermore, the present disclosure can be realized as a semiconductor integrated circuit that realizes part or all of the communication device or relay device, or as a communication system including the communication device or relay device. Effect of the Invention

[0011] According to the above aspect, the entire period from when the data transmission is instructed to when the data is determined is calculated. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration of a main part of a communication system according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of a relay method of the relay device. [Diagram 3] FIG. 2 is an explanatory diagram of operations performed in a transmission buffer. [Figure 4] FIG. 11 is an explanatory diagram of a determination method performed by a relay device. [Diagram 5] 13 is a diagram showing the relationship between judgment times and actions. [Figure 6] 2 is a block diagram showing a main configuration of a relay device; FIG. [Figure 7]FIG. 11 is an explanatory diagram of a device delay time. [Figure 8] 11 is a table showing the contents of target data. [Figure 9] FIG. 2 is a block diagram showing a main configuration of an in-vehicle device. [Figure 10] FIG. 11 is an explanatory diagram of device delay time. [Figure 11] 10 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device. [Figure 12] 10 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device. [Figure 13] 13 is a flowchart showing a procedure for a frame transmission process. [Figure 14] 13 is a flowchart showing a procedure of a first relay process of the transmission buffer. [Figure 15] 10 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device in the second embodiment. [Figure 16] 10 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device in the second embodiment. [Figure 17] 11 is a table showing the contents of frame data. [Figure 18] FIG. 11 is a block diagram showing a configuration of a main part of a relay device according to a third embodiment. [Figure 19] FIG. 2 is a block diagram showing a main configuration of an in-vehicle device. [Figure 20] 10 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device. [Figure 21] 13 is a flowchart showing an initial setting procedure performed by a relay device and an in-vehicle device in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. At least a part of the embodiments described below may be arbitrarily combined.

[0014] (1) A communication device according to one embodiment of the present disclosure is a communication device that transmits data to a relay device that transmits the received data, and includes a processing unit that executes processing, wherein the processing unit instructs the relay device to transmit data, obtains a transmission delay time from when the data transmission is instructed to when the data is transmitted, obtains a judgment delay time from when the relay device receives data to a judgment point at which it is determined whether to transmit the received data, and calculates an overall period from when the data transmission is instructed to the judgment point based on the acquired transmission delay time and judgment delay time.

[0015] (2) In a communication device according to an embodiment of the present disclosure, permitted periods during which transmission of received data is permitted and prohibited periods during which transmission of received data is prohibited are set in an alternating and repeated manner.

[0016] (3) In a communication device according to an aspect of the present disclosure, the processing unit determines the time to instruct transmission of data based on the calculated overall period.

[0017] (4) In a communication device according to one embodiment of the present disclosure, the processing unit calculates a propagation time from when data is transmitted to when the data is received, and calculates the total period based on the acquired transmission delay time and judgment delay time and the calculated propagation time.

[0018] (5) In a communication device according to an aspect of the present disclosure, the processing unit obtains a transmission delay time and a determination delay time associated with a data amount of data to be transmitted to the relay device.

[0019] (6) A relay device according to one embodiment of the present disclosure is a relay device that transmits data received from a communication device, and includes a receiving unit that receives data from the communication device and a processing unit that performs processing. When the receiving unit receives data, the processing unit determines whether or not to transmit the received data, obtains a transmission delay time from when the communication device is instructed to transmit the data to when the data is transmitted, obtains a judgment delay time from when the receiving unit receives the data to a judgment point at which it is determined whether or not to transmit the received data, and calculates an overall period from when the communication device is instructed to transmit data to the judgment point based on the obtained transmission delay time and judgment delay time.

[0020] (7) In a relay device according to one embodiment of the present disclosure, permitted periods during which transmission of data received by the receiving unit is permitted and prohibited periods during which transmission of data received by the receiving unit is prohibited are set alternately and repeatedly, and the processing unit determines that the receiving unit will transmit the data received if the determination time falls within the permitted period.

[0021] (8) In a relay device according to one embodiment of the present disclosure, the processing unit calculates a judgment point for data received by the receiving unit based on the calculated overall period, and adjusts the start point or length of the permitted period based on the calculated judgment point.

[0022] (9) A communication method according to one aspect of the present disclosure is a communication method for communicating data, the method including the steps of: acquiring a transmission delay time from when a communication device instructs a relay device to transmit received data to when the data is transmitted; acquiring a determination delay time from when the relay device receives data to a determination time at which it is determined whether or not to transmit the received data; and calculating an overall period from when a data transmission is instructed to the determination time based on the acquired transmission delay time and determination delay time.

[0023] In the above aspects, for the communication device, the relay device, and the communication method, the transmission delay time and the determination delay time are, for example, measured in advance. A processing unit of the communication device or the relay device, or a computer calculates the entire period from when an instruction to transmit data is issued to the time of determination based on the transmission delay time and the determination delay time that are measured in advance.

[0024] In the above aspect, the permitted period and the prohibited period are set alternately and repeatedly for the communication device and the relay device. In the relay device, if the determination time point belongs to the permitted period, transmission of the received data is instructed.

[0025] In the above aspect, the communication device determines the time to instruct transmission based on the calculated overall period so that the determination time falls within the permitted period. The communication device instructs the relay device to transmit data at the determined time. This allows the relay device to quickly transmit the received data.

[0026] In the above aspect, the communication device calculates a propagation time from when the data is transmitted to when the data is received by the relay device, and calculates an overall period by adding up the transmission delay time, the propagation time, and the determination delay time.

[0027] In the above aspect, the communication device acquires a transmission delay time and a determination delay time associated with a data amount. The communication device calculates an overall period corresponding to the data amount of data to be transmitted. The communication device determines, for example, a time point to instruct transmission of data based on the calculated overall period.

[0028] In the above aspect, the relay device calculates the determination time based on the entire period. The relay device adjusts the start time or the length of the permitted period based on the calculated determination time, for example, so that the determination time of the data received from the communication device belongs to the permitted period.

[0029] [Details of the embodiment of the present disclosure] Specific examples of communication systems according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0030] (Embodiment 1) <Communication system configuration> FIG. 1 is a block diagram showing a main configuration of a communication system 1 in the first embodiment. The communication system 1 is mounted on a vehicle M. The communication system 1 includes a relay device 10, two ECUs 11 and 12, and an in-vehicle device 13. ECU is an abbreviation for Electronic Control Unit. The two ECUs 11 and 12 are connected to the relay device 10 separately. A connection connector 10a is further connected to the relay device 10. The in-vehicle device 13 is detachably connected to the connection connector 10a.

[0031] Each of the ECUs 11 and 12 and the in-vehicle device 13 functions as a communication device. Each of the ECUs 11 and 12 and the in-vehicle device 13 transmits and receives data frames. A data frame is data composed of a plurality of bits. The relay device 10 receives data frames from each of the ECUs 11 and 12 and the in-vehicle device 13. The relay device 10 transmits data frames to each of the ECUs 11 and 12 and the in-vehicle device 13. The relay device 10 transmits the data frame received from the ECU 11 to the ECU 12 or the in-vehicle device 13. The relay device 10 transmits the data frame received from the ECU 12 to the ECU 11 or the in-vehicle device 13. The relay device 10 transmits the data frame received from the in-vehicle device 13 to the ECU 11 or the ECU 12.

[0032] Each of the ECUs 11 and 12 and the in-vehicle device 13 transmits a data frame including sensor data or instruction data to the relay device 10. The sensor data indicates a detection value detected by a sensor. The vehicle M has, for example, a reception unit that receives instructions from an occupant. The instruction data indicates, for example, an instruction received by the reception unit. The instruction data indicates, for example, an instruction to lock or unlock a door. Each of the ECUs 11 and 12 is connected to an electric device. Each of the ECUs 11 and 12 controls the operation of the electric device by outputting a control signal to the electric device. Each of the ECUs 11 and 12 determines an operation to be performed by the electric device based on the data frame received via the relay device 10, and causes the electric device to execute the determined operation. When the in-vehicle device 13 receives a data frame via the relay device 10, it performs an operation based on the received data frame.

[0033] <Operation of Relay Device 10> Fig. 2 is an explanatory diagram of a relay method of the relay device 10. The relay device 10 has a device storage unit 24 (see Fig. 6). As shown in Fig. 2, the device storage unit 24 is provided with three receiving buffers R1, R2, and R3 and three transmitting buffers T1, T2, and T3 as storage areas. The relay device 10 writes data frames received from the ECUs 11 and 12 and the in-vehicle device 13, respectively, into the receiving buffers R1, R2, and R3.

[0034] Data frames whose destinations are ECUs 11, 12 and in-vehicle equipment 13 are written into transmission buffers T1, T2, and T3, respectively. The data frames indicate the destinations. Relay device 10 moves data frames whose destination is ECU 11 among the data frames stored in reception buffers R2, R3 to transmission buffer T1. Moves data frames whose destination is ECU 12 among the data frames stored in reception buffers R1, R3 to transmission buffer T2. Moves data frames whose destination is in-vehicle equipment 13 among the data frames stored in reception buffers R1, R2 to transmission buffer T3.

[0035] The relay device 10 transmits the data frames stored in the transmission buffers T1, T2, and T3 to the ECUs 11 and 12 and the in-vehicle device 13.

[0036] 3 is an explanatory diagram of the operation performed in the transmission buffer T1. Each of the transmission buffers T1, T2, and T3 is provided with a first queue Q1 and a second queue Q2 as a storage area. Each of the ECUs 11 and 12 and the in-vehicle device 13 transmits two types of data frames. In the following, the two types of data frames are referred to as a first data frame and a second data frame, respectively.

[0037] The relay device 10 writes a first data frame, the destination of which is the ECU 11, to the first queue Q1 in the transmission buffer T1. Furthermore, the relay device 10 writes a second data frame, the destination of which is the ECU 11, to the second queue Q2 in the transmission buffer T1. The writing performed by the relay device 10 in each of the transmission buffers T2 and T3 is similar to the writing performed by the relay device 10 in the transmission buffer T1. The relay device 10 writes a first data frame and a second data frame, the destination of which is the ECU 12, to the first queue Q1 and the second queue Q2 in the transmission buffer T2, respectively. The relay device 10 writes a first data frame and a second data frame, the destination of which is the in-vehicle device 13, to the first queue Q1 and the second queue Q2 in the transmission buffer T3, respectively.

[0038] In each of the transmission buffers T1, T2, and T3, the relay device 10 determines whether or not to transmit the first data frame stored in the first queue Q1. If the relay device 10 determines to transmit the first data frame, the relay device 10 is instructed to transmit the first data frame. After the first data frame is transmitted, the relay device 10 discards the transmitted first data frame. The discarding of the data frame is achieved by deleting the data frame from the device storage unit 24.

[0039] When the relay device 10 determines not to transmit the first data frame, it discards the first data frame without transmitting it. The relay device 10 performs a determination on the first data frame according to the order in which the data frame was written to the first queue Q1. The earlier the first data frame is written to the first queue Q1, the earlier the determination is performed.

[0040] Similarly, for each of the transmission buffers T1, T2, and T3, the relay device 10 determines whether or not to transmit the second data frame stored in the second queue Q2. If the relay device 10 determines to transmit the second data frame, the relay device 10 is instructed to transmit the second data frame. After the second data frame is transmitted, the relay device 10 discards the transmitted second data frame. If the relay device 10 determines not to transmit the second data frame, the relay device 10 discards the second data frame without transmitting it. The determination of the second data frame is made according to the order in which the data were written to the second queue Q2.

[0041] Fig. 4 is an explanatory diagram of a determination method performed by the relay device 10. Fig. 4 shows a method of determining the first data frame and the second data frame stored in the transmission buffer T1. The relay device 10 has a master counter 20 (see Fig. 6). A count value is stored in the master counter 20. Fig. 4 shows the count value of the master counter 20.

[0042] A certain count number is determined in advance. The count number is 2 or more. The master counter 20 increments the count value by 1 each time the certain period elapses. When the count value is (count number)-1, the master counter 20 resets the count value to zero when the certain period elapses. In the example of FIG. 4, the count number is 125. One period is expressed as (count number)·(certain period). "·" represents a product.

[0043] As shown in Fig. 4, an open period and a closed period are set in association with the count value for each of the first queue Q1 and the second queue Q2. In the example of Fig. 4, for the first queue Q1, a period in which the count value is a value in the range from 0 to 74 is an open period. For the first queue Q1, a period in which the count value is a value in the range from 75 to 124 is a closed period. For the second queue Q2, a period in which the count value is a value in the range from 0 to 74 is a closed period. For the second queue Q2, a period in which the count value is a value in the range from 75 to 124 is an open period.

[0044] In Fig. 4, the first data frame is represented by a white rectangle. The second data frame is represented by a black rectangle. The time points at which the relay device 10 determines whether to transmit the first data frame and the second data frame received from the ECU 12 are shown. Similarly, the time points at which the relay device 10 determines whether to transmit the first data frame and the second data frame received from the in-vehicle device 13 are shown. The first data frame and the second data frame to be transmitted to the ECU 11 are shown.

[0045] Fig. 5 is a diagram showing the relationship between the judgment time and the operation. As shown in Figs. 4 and 5, a first data frame whose judgment time belongs to the open period of the first queue Q1 is permitted to be transmitted to the ECU 11. This first data frame is quickly transmitted to the ECU 11 by the relay device 10. The transmitted first data frame is discarded. A first data frame whose judgment time belongs to the close period of the first queue Q1 is discarded.

[0046] Similarly, the second data frame whose determination time falls within the open period of the second queue Q2 is permitted to be transmitted to the ECU 11. The second data frame is quickly transmitted to the ECU 11 by the relay device 10. The transmitted second data frame is discarded. The second data frame whose determination time falls within the closed period of the second queue Q2 is discarded.

[0047] The method of determining the first and second data frames stored in the transmission buffers T2 and T3 is the same as the method of determining the first and second data frames stored in the transmission buffer T1. In the method of determining the first and second data frames stored in the transmission buffer T2, the senders are the ECU 11 and the in-vehicle device 13, and the destination is the ECU 12. In the method of determining the first and second data frames stored in the transmission buffer T3, the senders are the ECUs 11 and 12, and the destination is the in-vehicle device 13.

[0048] As described above, the relay device 10 transmits and discards data frames in accordance with the IEEE802.1Qbv and IEEE802.1Qci standards. IEEE is a registered trademark and is an abbreviation for the Institute of Electrical and Electronics Engineers. The open period is a period during which the relay device 10 is permitted to transmit data frames received, and corresponds to the permitted period. The closed period is a period during which the relay device 10 is prohibited from transmitting data frames received, and corresponds to the prohibited period. As described above, when the count value is (count number)-1, the master counter 20 returns the count value to zero after a certain period has elapsed. Therefore, the open period and the prohibited period are set alternately and repeatedly.

[0049] <Configuration of Relay Device 10> 6 is a block diagram showing the main configuration of the relay device 10. As described above, the relay device 10 has the master counter 20 and the device storage unit 24. The relay device 10 further has two ECU communication ICs 21 and 22, a device communication IC 23, and a device control unit 25. IC is an abbreviation for Integrated Circuit. The master counter 20, the ECU communication ICs 21 and 22, the device communication IC 23, the device storage unit 24, and the device control unit 25 are connected to a device bus 26. The ECU communication ICs 21 and 22 are further connected to the ECUs 11 and 12, respectively. The device communication IC 23 is connected to the connector 10a. As described above, the connector 10a is connected to the in-vehicle device 13.

[0050] The ECU communication ICs 21, 22 and the device communication IC 23 each receive data frames, request data, etc. from the ECUs 11, 12 and the in-vehicle device 13. The device communication IC 23 functions as a receiver. The data frames received by the relay device 10 are data frames received by the ECU communication ICs 21, 22 and the device communication IC 23. The ECU communication ICs 21, 22 and the device communication IC 23 each transmit data frames, response data, count data, device delay data, target data, etc. to the ECUs 11, 12 and the in-vehicle device 13 according to instructions from the device control unit 25.

[0051] The request data is data that requests transmission of response data. The response data is data that is transmitted when the request data is received. The count data indicates the count value of the master counter 20. The device delay data indicates the device delay time. The target data indicates a target time point.

[0052] FIG. 7 is an explanatory diagram of the device delay time. The device delay time is the period from when one of the ECU communication ICs 21, 22 and the device communication IC 23 receives a data frame to the determination point at which it is determined whether or not to transmit the received data. The device delay time corresponds to the determination delay time. The device delay time is associated with the amount of data in the data frame transmitted to the relay device 10. The device delay time is longer as the amount of data in the data frame received by the relay device 10 is larger. The device delay time and the amount of data in the data frame are denoted as Yr and Xd, respectively. The device delay time Yr is approximated, for example, by the following equation (1). Yr = Ca Xd + Cb (1)

[0053] Ca and Cb are each a constant. The constant Ca is greater than zero. The device delay data indicates the device delay time Yr corresponding to the data amount Xd. Specifically, the device delay data indicates the formula (1). The device delay time Yr is measured in advance.

[0054] Fig. 8 is a table showing the contents of the target data. The target data indicates the target time points of the first data frame and the second data frame. The target time point is the count value of the master counter 20 at which to determine whether or not to transmit the data frame. Fig. 8 shows the target data used by the in-vehicle device 13. In this case, the in-vehicle device 13 transmits the first data frame and the second data frame to the device communication IC 23 so that the determination time point for determining whether or not to transmit the data frame is the target time point.

[0055] 8, the in-vehicle device 13 transmits a first data frame whose destination is the ECU 11 so as to determine whether or not to transmit the first data frame when the count value of the master counter 20 is 25. The in-vehicle device 13 transmits a first data frame whose destination is the ECU 12 so as to determine whether or not to transmit the first data frame when the count value of the master counter 20 is zero.

[0056] The in-vehicle device 13 transmits a second data frame whose destination is the ECU 11 so as to determine whether or not to transmit the second data frame when the count value of the master counter 20 is 100. The in-vehicle device 13 transmits a second data frame whose destination is the ECU 12 so as to determine whether or not to transmit the second data frame when the count value of the master counter 20 is 50.

[0057] The contents of the target data used by each of ECUs 11 and 12 are similar to the contents of the target data used by the in-vehicle device 13. The target data used by ECU 11 indicates the contents of a data frame whose destination is ECU 12 or the in-vehicle device 13. The target data used by ECU 12 indicates the contents of a data frame whose destination is ECU 11 or the in-vehicle device 13. It is preferable that the target time points of multiple first data frames having the same destination and different sources are different from each other. Similarly, it is preferable that the target time points of multiple second data frames having the same destination and different sources are different from each other.

[0058] The device storage unit 24 shown in Fig. 6 stores device delay data. The device control unit 25 has a processing element that executes processing, for example, a CPU (Central Processing Unit). The device control unit 25 functions as a processing unit. The device storage unit 24 further stores a computer program Pr. The computer program Pr is a program product. The processing element (computer) of the device control unit 25 executes the computer program Pr to perform data transmission processing, data movement processing, first relay processing and second relay processing of the transmission buffer T1, first relay processing and second relay processing of the transmission buffer T2, and first relay processing and second relay processing of the transmission buffer T3, etc.

[0059] The data transmission process is a process for transmitting count data, request data, device delay data, target data, etc. The data movement process is a process for moving a data frame from one of the receiving buffers R1, R2, R3 to at least one of the transmitting buffers T1, T2, T3. The first relay process is a process for relaying a first data frame. The second relay process is a process for relaying a second data frame.

[0060] The computer program Pr may be provided to the relay device 10 using a non-transitory storage medium Ar that readably stores the computer program Pr. The storage medium Ar is, for example, a portable memory. Examples of the portable memory include a CD-ROM, a Universal Serial Bus (USB) memory, an SD card, a micro SD card, and a Compact Flash (registered trademark). When the storage medium Ar is a portable memory, the processing element of the device control unit 25 may read the computer program Pr from the storage medium Ar using a reading device (not shown). The read computer program Pr is written to the device storage unit 24. Furthermore, the computer program Pr may be provided to the relay device 10 by a communication unit (not shown) of the relay device 10 communicating with an external device. In this case, the processing element of the device control unit 25 acquires the computer program Pr through the communication unit. The acquired computer program Pr is written to the device storage unit 24.

[0061] Furthermore, the number of processing elements included in device control unit 25 is not limited to 1, and may be 2 or more. When device control unit 25 has multiple processing elements, the multiple processing elements may cooperate to execute data transmission processing, the first relay processing and second relay processing of transmission buffer T1, the first relay processing and second relay processing of transmission buffer T2, and the first relay processing and second relay processing of transmission buffer T3, etc.

[0062] The device storage unit 24 is composed of, for example, a non-volatile memory and a volatile memory. In this case, for example, a computer program Pr, device delay data, target data, etc. are stored in the non-volatile memory of the device storage unit 24. For example, three receiving buffers R1, R2, R3 and three sending buffers T1, T2, T3 are provided in the storage area of ​​the volatile memory of the device storage unit 24.

[0063] <Configuration of in-vehicle device 13> 9 is a block diagram showing the main configuration of the in-vehicle device 13. The in-vehicle device 13 has a slave counter 30, a device communication IC 31, a device storage unit 32, and a device control unit 33. These are connected to a device bus 34. The device communication IC 31 is further connected to a device connector 31a. The device connector 31a is detachably connected to the connection connector 10a.

[0064] A count value is stored in the slave counter 30. Like the master counter 20, the slave counter 30 increments the count value by one each time a certain period of time has elapsed. The certain period of time and the count number of the slave counter 30 are the same as those of the master counter 20. When the count value is (count number)-1, the slave counter 30 resets the count value to zero when a certain period of time has elapsed. The device control unit 33 synchronizes the count value of the slave counter 30 with the count value of the master counter 20.

[0065] The device communication IC 31 receives data frames, response data, count data, device delay data, target data, and the like from the device communication IC 23 of the relay device 10. The device communication IC 31 transmits data frames, request data, and the like according to instructions from the device control unit 33. The device storage unit 32 stores device delay data. The device delay data indicates a device delay time. Target data for the in-vehicle device 13 is written in the device storage unit 32.

[0066] FIG. 10 is an explanatory diagram of the equipment delay time. The equipment delay time is the period from when the equipment control unit 33 in the in-vehicle equipment 13 instructs the equipment communication IC 31 to transmit a data frame to the relay device 10 until the equipment communication IC 31 transmits the data frame. The equipment delay time corresponds to the transmission delay time. The equipment delay time is associated with the amount of data of the data frame transmitted to the relay device 10. The equipment delay time is longer as the amount of data of the transmitted data frame increases. The equipment delay time is denoted as Ye. The equipment delay time Ye is approximated, for example, by the following formula (2). Ye = Cc·Xd + Cd···(2)

[0067] Xd is the amount of data in the data frame as described above. Cc and Cd are each a constant. The constant Cc is greater than zero. The equipment delay data indicates the equipment delay time Ye corresponding to the data amount Xd. Specifically, the equipment delay data indicates equation (2). The equipment delay time Ye is measured in advance.

[0068] The device control unit 33 shown in Fig. 9 has a processing element, such as a CPU, that executes processing. The device control unit 33 functions as a processing unit. A computer program Pe is stored in the device storage unit 32. The computer program Pe is a program product. The processing element (computer) of the device control unit 33 executes the computer program Pe to execute adjustment processing, writing processing, frame transmission processing, and the like.

[0069] In the adjustment process, the device control unit 33 adjusts the count value of the slave counter 30. In the adjustment process, the device control unit 33 further writes propagation time data, device delay data, target data, etc., to the device memory unit 32. The write process is a process of writing a data frame to be transmitted to one of the ECUs 11, 12 to the device memory unit 32. The frame transmission process is a process of transmitting a data frame to the relay device 10. The propagation time data indicates a propagation time. The propagation time is the period from when the device communication IC 31 transmits the data frame to when the device communication IC 23 of the relay device 10 receives the data frame.

[0070] The computer program Pe may be provided to the in-vehicle device 13 using a non-transitory storage medium Ae that readably stores the computer program Pe. The storage medium Ae is, for example, a portable memory. When the storage medium Ae is a portable memory, the processing element of the device control unit 33 may read the computer program Pe from the storage medium Ae using a reading device (not shown). The read computer program Pe is written to the device storage unit 32. Furthermore, the computer program Pe may be provided to the in-vehicle device 13 by a communication unit (not shown) of the in-vehicle device 13 communicating with an external device. In this case, the processing element of the device control unit 33 acquires the computer program Pe through the communication unit. The acquired computer program Pe is written to the device storage unit 32.

[0071] Furthermore, the number of processing elements included in the device control unit 33 is not limited to 1, and may be 2 or more. When the device control unit 33 has multiple processing elements, the multiple processing elements may cooperate to execute the adjustment process, the frame transmission process, and the like.

[0072] The device storage unit 32 is configured with, for example, a non-volatile memory and a volatile memory. In this case, the non-volatile memory of the device storage unit 32 stores, for example, a computer program Pe, device delay data, propagation time data, device delay data, and target data.

[0073] <Initial settings> 11 and 12 are flowcharts showing the procedure of initial setting performed by the relay device 10 and the in-vehicle device 13. In the initial setting, the device control unit 25 of the relay device 10 executes a data transmission process. The device control unit 33 of the in-vehicle device 13 executes an adjustment process. The device control unit 25 of the relay device 10 executes a data transmission process when the in-vehicle device 13 is removed from the connection connector 10a. The device control unit 33 of the in-vehicle device 13 executes an adjustment process when the in-vehicle device 13 is connected to the connection connector 10a.

[0074] In the data transmission process, the device control unit 25 determines whether or not the in-vehicle device 13 is connected to the connector 10a (step S1). If the device control unit 25 determines that the in-vehicle device 13 is not connected to the connector 10a (S1: NO), it executes step S1 again and waits until the in-vehicle device 13 is connected to the connector 10a. If the device control unit 25 determines that the in-vehicle device 13 is connected to the connector 10a (S1: YES), it instructs the device communication IC 23 to transmit count data indicating the count value of the master counter 20 to the device communication IC 31 of the in-vehicle device 13 (step S2).

[0075] In the adjustment process, the device control unit 33 of the in-vehicle device 13 determines whether the device communication IC 31 has received the count data (step S11). If the device control unit 33 determines that the device communication IC 31 has not received the count data (S11: NO), it executes step S11 again and waits until the device communication IC 31 receives the count data. If the device control unit 33 determines that the device communication IC 31 has received the count data (S11: YES), it adjusts the count value of the slave counter 30 to the count value indicated by the count data received by the device communication IC 31 (step S12).

[0076] Next, the device control unit 33 instructs the device communication IC 31 to transmit the request data to the device communication IC 23 of the relay device 10 (step S13). The request data includes device transmission count information indicating the count value of the slave counter 30 at the time when the request data is transmitted. Hereinafter, the count value of the slave counter 30 at the time when the request data is transmitted is referred to as the device transmission count value.

[0077] After executing step S2, the device control unit 25 of the relay device 10 determines whether the device communication IC 23 has received the request data (step S3). If the device control unit 25 determines that the device communication IC 23 has not received the request data (S3: NO), it executes step S3 again and waits until the device communication IC 23 receives the request data. If the device control unit 25 determines that the device communication IC 23 has received the request data (S3: YES), it instructs the device communication IC 23 to transmit response data to the device communication IC 31 of the in-vehicle device 13 (step S4).

[0078] The response data includes the device transmission count information, device reception count information, and device transmission count information contained in the request data. The device reception count information indicates the count value of the master counter 20 at the time when the device communication IC 23 receives the request data. The device transmission count information indicates the count value of the master counter 20 at the time when the device communication IC 23 transmits the response data. Hereinafter, the count value of the master counter 20 at the time when the device communication IC 23 receives the request data is referred to as the device reception count value. The count value of the master counter 20 at the time when the device communication IC 23 transmits the response data is referred to as the device transmission count value.

[0079] After executing step S13, the device control unit 33 of the in-vehicle device 13 determines whether the device communication IC 31 has received response data from the device communication IC 23 of the relay device 10 (step S14). If the device control unit 33 determines that the device communication IC 31 has not received the response data (S14: NO), it executes step S14 again and waits until the device communication IC 31 receives the response data.

[0080] Hereinafter, the count value of the slave counter 30 at the time when the device communication IC 31 receives the response data will be referred to as a device reception count value. As described above, the response data includes device transmission count information, device reception count information, and device transmission count information.

[0081] The equipment sending count value, equipment receiving count value, equipment sending count value, and equipment receiving count value are represented by Het, Hrr, Hrt, and Her, respectively. The propagation times of the request data and the response data are assumed to be the same. In this case, the difference Hd between the count values ​​of the master counter 20 and the slave counter 30 is expressed by the following formula (3). Hd=((Hrr-Het)-(Her-Hrt)) / 2···(3)

[0082] When the device control unit 33 determines that the device communication IC 31 has received the response data (S14: YES), it executes fine adjustment of the count value of the slave counter 30 based on the difference Hd (step S15). As described above, when the device communication IC 31 of the in-vehicle device 13 receives count data from the device communication IC 23 of the relay device 10, the device control unit 33 adjusts the count value of the slave counter 30 to the count value indicated by the count data received by the device communication IC 31. Therefore, the count value of the slave counter 30 is smaller than the actual count value of the master counter 20.

[0083] In step S15, the device control unit 33 increases the count value of the slave counter 30 by the absolute value of the difference Hd. As a result, the count value of the slave counter 30 substantially matches the count value of the master counter 20. The method for calculating the difference Hd is not limited to the method using equation (3).

[0084] Next, the device control unit 33 calculates the propagation time of the data frame based on the device transmission count value Het, the device reception count value Hrr, the device transmission count value Hrt, and the device reception count value Her (step S16). The propagation time of the data frame is considered to be the same as the propagation time of the request data (response data). The propagation time of the data frame is written as Ht. The propagation time Ht is expressed by the following formula (4). Ht=((Hrr-Het)+(Her-Hrt)) / 2···(4) The method for calculating the propagation time Ht is not limited to the method using equation (4).

[0085] Regarding formulas (3) and (4), if Hrr is smaller than Het, the value required for the count value to change from Het to Hrr is used as (Hrr-Het).If Hrt is smaller than Her, the value required for the count value to change from Hrt to Her is used as (Her-Hrt).

[0086] Next, the device control unit 33 writes the propagation time data indicating the propagation time calculated in step S16 to the device storage unit 32 (step S17). After executing step S4, the device control unit 25 of the relay device 10 instructs the device communication IC 23 to transmit the device delay data stored in the device storage unit 24 to the device communication IC 31 of the in-vehicle device 13 (step S5).

[0087] After executing step S17, the device control unit 33 of the in-vehicle device 13 determines whether or not the device communication IC 31 has received device delay data from the device communication IC 23 (step S18). If the device control unit 33 determines that the device communication IC 31 has not received device delay data (S18: NO), it executes step S18 again and waits until the device communication IC 31 receives the device delay data.

[0088] When the device control unit 33 determines that the device communication IC 31 has received the device delay data (S18: YES), the device control unit 33 writes the device delay data received by the device communication IC 31 to the device storage unit 32 (step S19). After executing step S5, the device control unit 25 of the relay device 10 instructs the device communication IC 23 to transmit target data for the in-vehicle device 13 to the device communication IC 31 of the in-vehicle device 13 (step S6). As described above, the target data for the in-vehicle device 13 is stored in the device storage unit 24. After executing step S6, the device control unit 25 ends the data transmission process. If the in-vehicle device 13 is removed from the connection connector 10a, the device control unit 25 executes the data transmission process again.

[0089] After executing step S19, the device control unit 33 of the in-vehicle device 13 determines whether or not the device communication IC 31 has received target data for the in-vehicle device 13 from the device communication IC 23 (step S20). When the device control unit 33 determines that the device communication IC 31 has not received target data for the in-vehicle device 13 (S20: NO), it executes step S20 again and waits until the device communication IC 31 receives the target data for the in-vehicle device 13.

[0090] When the device control unit 33 determines that the device communication IC 31 has received the target data for the in-vehicle device 13 (S20: YES), the device control unit 33 writes the target data for the in-vehicle device 13 received by the device communication IC 31 to the device storage unit 32 (step S21). After executing step S21, the device control unit 33 ends the adjustment process. When the in-vehicle device 13 is reconnected to the connection connector 10a after being removed from the connection connector 10a, the device control unit 33 executes the adjustment process again.

[0091] As described above, when the device control unit 25 and the equipment control unit 33 execute the data transmission process and the adjustment process, respectively, the count values ​​of the master counter 20 and the slave counter 30 substantially match. Also, the equipment storage unit 32 of the in-vehicle equipment 13 stores the equipment delay data, the propagation time data, and the equipment delay data.

[0092] If the count number and the fixed period of the slave counter 30 do not match the count number and the fixed period of the master counter 20, in step S2, the device communication IC 23 of the relay device 10 transmits count data indicating the count value, count number, and fixed period of the master counter 20 to the device communication IC 31 of the in-vehicle device 13. When the device communication IC 31 receives the count data, the device control unit 33 adjusts the count value, count number, and fixed period of the slave counter 30 to the count value, count number, and fixed period indicated by the count data.

[0093] <Writing of data frame by in-vehicle device 13> As described above, the device control unit 33 of the in-vehicle device 13 executes the write process. In the case where the in-vehicle device 13 has a sensor, when sensor data is input from the sensor, in the write process, the device control unit 33 generates a data frame including the input sensor data. In the case where the in-vehicle device 13 has a reception unit that receives instructions, when the reception unit receives an instruction, in the write process, the device control unit 33 generates a data frame including instruction data indicating the received instruction. The device control unit 33 writes the generated data frame to the device storage unit 32. The data frame generated by the device control unit 33 is a first data frame or a second data frame.

[0094] <Transmission of data frames by the in-vehicle device 13> 13 is a flowchart showing the procedure of the frame transmission process. As described above, the device delay data, the propagation time data, and the device delay data are stored in the device storage unit 32. When a data frame is written to the device storage unit 32, the device control unit 33 of the in-vehicle device 13 executes the frame transmission process. In the frame transmission process, the device control unit 33 acquires the device delay data, the propagation time data, and the device delay data from the device storage unit 32 (step S31). The acquisition of the device delay data corresponds to the acquisition of the device delay time associated with the data amount of the data frame. The acquisition of the device delay data corresponds to the acquisition of the device delay time associated with the data amount of the data frame.

[0095] Next, the device control unit 33 calculates the device delay time and the device delay time corresponding to the data amount of the data frame stored in the device memory unit 32 based on the device delay data and the device delay data acquired in step S31 (step S32).

[0096] Next, the device control unit 33 calculates an overall period corresponding to the amount of data of the data frames stored in the device storage unit 32 based on the device delay time and device delay time calculated in step S32 and the propagation time indicated by the propagation time data (step S33). The overall period is the period from when the device control unit 33 instructs the in-vehicle device 13 to transmit the data frame to the determination point in time. The overall period is calculated as the sum of the device delay time, the propagation time, and the device delay time.

[0097] Next, the device control unit 33 determines a transmission instruction value based on the target time point indicated by the target data and the entire period calculated in step S33 (step S34). The transmission instruction value is the count value (time point) of the slave counter 30 at which the device control unit 33 instructs the transmission of a data frame.

[0098] It is assumed that the data frame stored in the device storage unit 32 is a second data frame whose destination is the ECU 11. In this case, as shown in FIG. 8, the target time point of the second data frame is 100. It is assumed that the width of the count value obtained by dividing the entire period by a fixed period is 30. In this case, the transmission instruction value is 70 (=100-30). It is assumed that the data frame stored in the device storage unit 32 is a first data frame whose destination is the ECU 11. In this case, the target time point of the first data frame is 25. When the count number is 125, the transmission instruction value is 120 (=25-30+125).

[0099] After executing step S34, the device control unit 33 determines whether the count value of the slave counter 30 is the transmission instruction value determined in step S34 (step S35). If the device control unit 33 determines that the count value is not the transmission instruction value (S35: NO), it executes step S35 again and waits until the count value becomes the transmission instruction value.

[0100] When the machine control unit 33 determines that the count value is the transmission instruction value (S35: YES), it instructs the device communication IC 31 to transmit the data frame stored in the device storage unit 32 to the relay device 10 (step S36). After executing step S36, the machine control unit 33 ends the frame transmission process.

[0101] <Transmission of data frames performed by ECUs 11 and 12> Each of ECUs 11 and 12 is configured in the same way as in-vehicle device 13. When each of ECUs 11 and 12 is connected to relay device 10, each of ECUs 11 and 12 makes the count value of slave counter 30 match the count value of master counter 20, in the same way as in-vehicle device 13. Each of ECUs 11 and 12 calculates the propagation time, in the same way as in-vehicle device 13. Relay device 10 transmits device delay data to each of ECUs 11 and 12. Relay device 10 transmits target data for ECU 11 and target data for ECU 12 to each of ECUs 11 and 12. In each of ECUs 11 and 12, frame transmission processing is executed, in the same way as in-vehicle device 13.

[0102] <Movement of data frames performed by relay device 10> As described above, the device control unit 25 of relay device 10 executes data movement processing. In the data movement processing, the device control unit 25 writes the data frames received by each of ECU communication ICs 21 and 22 and device communication IC 23 into reception buffers R1, R2, and R3. The device control unit 25 moves the data frames whose transmission destination is ECU 11 among the data frames stored in reception buffers R2 and R3 to transmission buffer T1. Here, the device control unit 25 moves the first data frame to the first queue Q1 of transmission buffer T1. The device control unit 25 moves the second data frame to the second queue Q2 of transmission buffer T1.

[0103] Similarly, the device control unit 25 transfers data frames whose destination is the ECU 12 to the transmission buffer T2 among the data frames stored in the reception buffers R1 and R3. Here, the device control unit 25 transfers the first data frame to the first queue Q1 of the transmission buffer T2. The device control unit 25 transfers the second data frame to the second queue Q2 of the transmission buffer T2. The device control unit 25 transfers data frames whose destination is the in-vehicle device 13 to the transmission buffer T3 among the data frames stored in the reception buffers R1 and R2. Here, the device control unit 25 transfers the first data frame to the first queue Q1 of the transmission buffer T3. The device control unit 25 transfers the second data frame to the second queue Q2 of the transmission buffer T3.

[0104] <Data Frame Relay by Relay Device 10> 14 is a flowchart showing the procedure of the first relay process of the transmission buffer T1. In the first relay process of the transmission buffer T1, the device control unit 25 of the relay device 10 determines whether or not a first data frame is stored in the first queue Q1 of the transmission buffer T1 (step S41). When the device control unit 25 determines that the first data frame is not stored in the first queue Q1 (S41: NO), it executes step S41 again and waits until the first data frame is stored in the first queue Q1.

[0105] When the device control unit 25 determines that the first data frame is stored in the first queue Q1 (S41: YES), it reads the count value of the master counter 20 (step S42). Next, the device control unit 25 determines whether or not to transmit the first data frame stored in the first queue Q1 to the ECU 11 based on the count value read in step S42 (step S43).

[0106] The count value read in step S42 corresponds to a determination point in time for determining whether or not to transmit the first data frame. In step S43, if the count value read in step S42 belongs to the open period of the first queue Q1, the device control unit 25 determines to transmit the first data frame stored in the first queue Q1. If the count value read in step S42 belongs to the closed period of the first queue Q1, the device control unit 25 determines not to transmit the first data frame.

[0107] When the device control unit 25 determines to transmit the first data frame (S43: YES), it instructs the ECU communication IC 21 to transmit the first data frame stored in the first queue Q1 (step S44). As a result, the first data frame is transmitted to the ECU 11. When the device control unit 25 determines not to transmit the first data frame (S43: NO), it discards the first data frame (step S45). After executing one of steps S44 and S45, the device control unit 25 ends the first relay process of the transmission buffer T1. Thereafter, the device control unit 25 executes the first relay process of the transmission buffer T1.

[0108] The device control unit 25 executes the second relay process of the transmission buffer T1 in the same manner as the first relay process of the transmission buffer T1. In the explanation of the first relay process of the transmission buffer T1, the second relay process of the transmission buffer T1 can be explained by replacing the first data frame and the first queue Q1 with the second data frame and the second queue Q2, respectively.

[0109] The first and second relay processes of the transmission buffer T2 are similar to the first and second relay processes of the transmission buffer T1. In the description of the first and second relay processes of the transmission buffer T1, the transmission buffer T1 and the ECU 11 are replaced with the transmission buffer T2 and the ECU 12, respectively. This makes it possible to describe the first and second relay processes of the transmission buffer T2.

[0110] The first and second relay processes of the transmission buffer T3 are similar to those of the transmission buffer T1. In the description of the first and second relay processes of the transmission buffer T1, the transmission buffer T1 and the ECU 11 are replaced with the transmission buffer T3 and the in-vehicle device 13, respectively. This makes it possible to describe the first and second relay processes of the transmission buffer T3.

[0111] <Effects of Communication System 1> In the in-vehicle device 13, the device control unit 33 determines a transmission instruction value based on the calculated overall period so that the determination time point at which the device control unit 25 of the relay device 10 determines whether to transmit a data frame belongs to the open period. The device control unit 33 transmits a data frame when the count value of the slave counter 30 is equal to the determined transmission instruction value. Therefore, the relay device 10 quickly transmits the received data frame.

[0112] (Embodiment 2) In the first embodiment, the time point at which the device control unit 33 of the in-vehicle device 13 instructs transmission of a data frame is adjusted based on the entire period. However, the target to be adjusted based on the entire period may be different from the time point at which the device control unit 33 instructs transmission of a data frame. The following describes the differences between embodiment 2 and embodiment 1. Since the configurations other than those described below are common to embodiment 1, the components common to embodiment 1 are given the same reference numerals as embodiment 1 and descriptions thereof will be omitted.

[0113] <Overview of Communication System 1> In the frame transmission process, the device control unit 33 of the in-vehicle device 13 in the second embodiment does not execute steps S31 to S34, but executes steps S35 and S36. The transmission instruction value of the data frame is set in advance. Also, the data amount of the data frame transmitted by the device communication IC 31 of the in-vehicle device 13 is substantially constant. The relay device 10 adjusts the start point or the length of the open period based on the entire period.

[0114] <Initial settings> 15 and 16 are flowcharts showing the procedure of initial setting performed by the relay device 10 and the in-vehicle device 13 in the second embodiment. In the initial setting in the second embodiment, the device control unit 25 of the relay device 10 and the device control unit 33 of the in-vehicle device 13 each execute a data transmission process and an adjustment process, similar to the initial setting in the first embodiment. In the data transmission process in the second embodiment, the device control unit 25 of the relay device 10 executes steps S1 to S4, similar to the first embodiment. In the adjustment process in the second embodiment, the device control unit 33 of the in-vehicle device 13 executes steps S11 to S16, similar to the first embodiment.

[0115] In the adjustment process, the device control unit 33 of the in-vehicle device 13 executes step S16, and then instructs the device communication IC 31 to transmit propagation time data indicating the propagation delay time calculated in step S16 to the device communication IC 23 of the relay device 10 (step S71). In the data transmission process, the device control unit 25 of the relay device 10 executes step S4, and then determines whether the device communication IC 23 has received the propagation time data (step S51). When the device control unit 25 determines that the device communication IC 23 has not received the propagation time data (S51: NO), it executes step S51 again and waits until the device communication IC 23 receives the propagation time data.

[0116] When the device control unit 25 determines that the device communication IC 23 has received the propagation time data (S51: YES), it writes the propagation time data received by the device communication IC 23 to the device storage unit 24 (step S52). In the adjustment process, the device control unit 33 of the in-vehicle device 13 executes step S71, and then instructs the device communication IC 31 to transmit the device delay data stored in the device storage unit 32 to the device communication IC 23 of the relay device 10 (step S72). In the data transmission process, the device control unit 25 of the relay device 10 executes step S52, and then determines whether the device communication IC 23 has received the device delay data (step S53). When the device control unit 25 determines that the device communication IC 23 has not received the device delay data (S53: NO), it executes step S53 again, and waits until the device communication IC 23 receives the device delay data.

[0117] When the device control unit 25 determines that the device communication IC 23 has received the device delay data (S53: YES), it writes the device delay data received by the device communication IC 23 to the device storage unit 24 (step S54). In the adjustment process, after executing step S72, the device control unit 33 of the in-vehicle device 13 instructs the device communication IC 31 to transmit frame data of the data frame transmitted by the in-vehicle device 13 to the device communication IC 23 of the relay device 10 (step S73). The frame data of the data frame transmitted by the in-vehicle device 13 is stored in advance in the device storage unit 24.

[0118] Fig. 17 is a table showing the contents of the frame data. The frame data indicates the data amounts of the first and second data frames, and the transmission instruction values ​​of the first and second data frames. The transmission instruction values ​​are the count values ​​of the master counter 20 and the slave counter 30 after synchronization is achieved. Fig. 17 shows the frame data of the data frame transmitted by the in-vehicle device 13.

[0119] 17, for a first data frame whose destination is ECU 11, the amount of data is 140 bytes and the transmission instruction value is zero. For a first data frame whose destination is ECU 12, the amount of data is 150 bytes and the transmission instruction value is 25. For a second data frame whose destination is ECU 11, the amount of data is 160 bytes and the transmission instruction value is 50. For a second data frame whose destination is ECU 12, the amount of data is 170 bytes and the transmission instruction value is 100.

[0120] The contents of the frame data of the data frames transmitted by each of the ECUs 11 and 12 are similar to the contents of the frame data of the data frame transmitted by the in-vehicle device 13. The destination of the data frame transmitted by the ECU 11 is the ECU 12 and the in-vehicle device 13. The destination of the data frame transmitted by the ECU 12 is the ECU 11 and the in-vehicle device 13. The frame data of the data frames transmitted by the ECUs 11 and 12 are stored in advance in the device memory unit 24.

[0121] 16, the device control unit 33 ends the adjustment process after executing step S73. When the in-vehicle device 13 is reconnected to the connector 10a after being disconnected from the connector 10a, the device control unit 33 executes the adjustment process again.

[0122] In the data transmission process, after executing step S54, the device control unit 25 of the relay device 10 determines whether or not the device communication IC 23 has received the frame data (step S55). If the device control unit 25 determines that the device communication IC 23 has not received the frame data (S55: NO), it executes step S55 again and waits until the device communication IC 23 receives the frame data. If the device control unit 25 determines that the device communication IC 23 has received the frame data (S55: YES), it writes the frame data to the device storage unit 24 (step S56).

[0123] Next, the device control unit 25 acquires the device delay data and the equipment delay data from the device storage unit 24 (step S57). Next, the device control unit 25 calculates the device delay time and the equipment delay time corresponding to each of the multiple data amounts indicated by the frame data based on the device delay data and the equipment delay data acquired in step S57 (step S58). Here, the multiple data amounts are the data amounts of the first data frame and the second data frame whose destination is the ECU 11, and the data amounts of the first data frame and the second data frame whose destination is the ECU 12.

[0124] Next, the device control unit 25 calculates a plurality of overall periods based on the propagation time indicated by the propagation time data and the device delay time and the equipment delay time calculated in step S58 (step S59). Here, the plurality of overall periods are the entire periods of the first and second data frames whose destination is the ECU 11, and the entire periods of the first and second data frames whose destination is the ECU 12. After executing step S59, the device control unit 25 calculates a plurality of determination time points based on the plurality of transmission instruction values ​​indicated by the frame data and the plurality of overall periods calculated in step S59 (step S60). Here, the plurality of determination time points are the determination time points of the first and second data frames whose destination is the ECU 11, and the determination time points of the first and second data frames whose destination is the ECU 12.

[0125] Assume that the width of the count value obtained by dividing the entire period of the first data frame whose destination is ECU 11 by a fixed period is 50. In the example of Fig. 17, the transmission instruction value of the first data frame whose destination is ECU 11 is zero. In this case, the determination time point of the first data frame whose destination is ECU 11 is 50 (=0+50).

[0126] Next, the device control unit 25 adjusts the open periods of the first queue Q1 and the second queue Q2 of the transmission buffers T1, T2 based on the multiple judgment points calculated in step S60 (step S61). The adjustment of the open period is an adjustment of the start point or length of the open period. In one cycle, the period other than the open period is a closed period. Therefore, when the start point and length of the open period are determined, the start point and length of the closed period are automatically determined. Each of the ECUs 11, 12 transmits the first data frame or the second data frame when the count value of the slave counter 30 is the transmission instruction value indicated by the frame data.

[0127] In step S61, the device control unit 25 adjusts the start point or length of the open period of the first queue Q1 for the transmission buffer T1 so that the determination points of all first data frames whose destination is the ECU 11 belong to the open period of the first queue Q1. The device control unit 25 also adjusts the start point or length of the open period of the second queue Q2 for the transmission buffer T1 so that the determination points of all second data frames whose destination is the ECU 11 belong to the open period of the second queue Q2. Furthermore, the device control unit 25 adjusts the start point or length of the open period of the first queue Q1 and the second queue Q2 of the transmission buffer T2 in the same way as the start point or length of the open period of the first queue Q1 and the second queue Q2 of the transmission buffer T1.

[0128] After executing step S61, the device control unit 25 ends the data transmission process. When the in-vehicle device 13 is removed from the connector 10a, the device control unit 25 executes the data transmission process again.

[0129] <Effects of Communication System 1> As described above, in the relay device 10, the device control unit 25 adjusts the start time or the length of the open period of the first queue Q1 and the second queue Q2 for each of the transmission buffers T1 and T2. Therefore, the relay device 10 quickly transmits the data frame received from the in-vehicle device 13 to the ECU 11 or ECU 12. The communication system 1 in embodiment 2 has the same effects as the communication system 1 in embodiment 1, except for the effect obtained by the device control unit 33 of the in-vehicle device 13 determining the transmission instruction value based on the entire period.

[0130] (Embodiment 3) In the first embodiment, the device control unit 33 of the in-vehicle device 13 uses the data amount of the data frame to calculate the entire period. However, the device control unit 33 may use other numerical values ​​in addition to the data amount of the data frame to calculate the entire period. The following describes the differences between the third embodiment and the first embodiment. Since the configurations other than those described below are the same as those of the first embodiment, the components common to the first embodiment are given the same reference numerals as those of the first embodiment, and the description thereof will be omitted.

[0131] <Configuration of Relay Device 10> 18 is a block diagram showing a main configuration of the relay device 10 in the third embodiment. The relay device 10 in the third embodiment has a device timer 27 in addition to the components of the relay device 10 in the first embodiment. The device timer 27 is connected to the device bus 26. The device timer 27 measures the device elapsed time that has elapsed since the relay device 10 was manufactured. The device elapsed time measured by the device timer 27 is read by the device control unit 25.

[0132] <Configuration of in-vehicle device 13> 19 is a block diagram showing the main configuration of the in-vehicle device 13. The in-vehicle device 13 in the third embodiment has a device timer 35 and a synchronous timer 36 in addition to the components of the in-vehicle device 13 in the first embodiment. The device timer 35 and the synchronous timer 36 are connected to the device bus 34. The device timer 35 measures the device elapsed time that has elapsed since the in-vehicle device 13 was manufactured. The device elapsed time measured by the device timer 35 is read by the device control unit 33.

[0133] The synchronization timer 36 measures time. The measured time measured by the synchronization timer 36 is synchronized with the device elapsed time measured by the device timer of the relay device 10. After synchronization is achieved, the measured time by the synchronization timer 36 is the device elapsed time. The measured time by the synchronization timer 36 is read by the device control unit 33.

[0134] <Initial settings> 20 is a flowchart showing the procedure of the initial setting performed by the relay device 10 and the in-vehicle device 13. In the initial setting of the third embodiment, similar to the initial setting of the first embodiment, the device control unit 25 of the relay device 10 and the device control unit 33 of the in-vehicle device 13 each execute a data transmission process and an adjustment process. In the data transmission process of the third embodiment, the device control unit 25 of the relay device 10 executes steps S1 to S6 similar to the first embodiment. In the adjustment process of the third embodiment, the device control unit 33 of the in-vehicle device 13 executes steps S11 to S21 similar to the first embodiment.

[0135] In the data transmission process, the device control unit 25 of the relay device 10 executes step S6 and then reads out the device elapsed time measured by the device timer 27 (step S81). Next, the device control unit 25 instructs the device communication IC 23 to transmit device timer data indicating the device elapsed time read out in step S81 to the device communication IC 31 of the in-vehicle device 13 (step S82). After executing step S82, the device control unit 25 ends the data transmission process. If the in-vehicle device 13 is removed from the connection connector 10a, the device control unit 25 executes the data transmission process again.

[0136] In the adjustment process, after executing step S21, the device control unit 33 determines whether the device communication IC 31 has received device timer data (step S91). If the device control unit 33 determines that the device communication IC 31 has not received device timer data (S91: NO), it executes step S91 again and waits until the device communication IC 31 receives the device timer data.

[0137] When the device control unit 33 determines that the device communication IC 31 has received the device timer data (S91: YES), it adjusts the measurement time of the synchronization timer 36 to the device elapsed time indicated by the device timer data (step S92). As a result, the measurement time of the synchronization timer 36 is synchronized with the device elapsed time measured by the device timer 27. After executing step S92, the device control unit 33 ends the adjustment process. If the in-vehicle device 13 is disconnected from the connection connector 10a and then reconnected to the connection connector 10a, the device control unit 33 executes the adjustment process again.

[0138] <Equipment Delay Data> The device delay data in the third embodiment indicates a device delay time corresponding to the data amount of a data frame transmitted to the relay device 10 and the device elapsed time. Specifically, the device delay data indicates a function formula for calculating the device delay time based on the data amount and the device elapsed time. Acquisition of the device delay data corresponds to acquisition of the device delay time associated with the data amount of the data frame and the device elapsed time.

[0139] <Equipment Delay Data> The device delay data in the third embodiment indicates a device delay time corresponding to the data amount of the data frame transmitted to the relay device 10 and the device elapsed time. Specifically, the device delay data indicates a function formula for calculating the device delay time based on the data amount and the device elapsed time. Acquisition of the device delay data corresponds to acquisition of the device delay time associated with the data amount of the data frame and the device elapsed time.

[0140] <Transmission of data frames by the in-vehicle device 13> In step S32 of the frame transmission process in Embodiment 3, the device control unit 33 calculates the device delay time and the device delay time based on the device delay data and the device delay data acquired in step S31. In step S33, the device control unit 33 calculates the device delay time corresponding to the data amount of the data frame stored in the device storage unit 32 and the device elapsed time of the device timer 35. Further, the device control unit 33 calculates the device delay time corresponding to the data amount of the data frame stored in the device storage unit 32 and the measurement time (device delay time) of the synchronization timer 36. In step S33, the device control unit 33 calculates the overall period using the device delay time and the device delay time calculated in step S32.

[0141] <Transmission of data frames performed by ECUs 11 and 12> Each of ECUs 11 and 12 is configured in the same manner as in-vehicle device 13. Each of ECUs 11 and 12 transmits a data frame in the same manner as in-vehicle device 13.

[0142] <Effect of communication system 1> In the overall period calculated by the device control unit 33 in in-vehicle device 13, the device elapsed time and the device elapsed time, that is, aging deterioration are taken into consideration. Therefore, the device control unit 33 calculates a transmission instruction value for which the determination time definitely belongs to the open period. The communication system 1 in Embodiment 3 exhibits the same effects as those exhibited by the communication system 1 in Embodiment 1.

[0143] (Embodiment 4) In Embodiment 2, the device control unit 25 of the relay device 10 uses the data amount of the data frame in the calculation of the overall period. However, the device control unit 25 may use other numerical values in addition to the data amount of the data frame in the calculation of the overall period. Hereinafter, the differences between Embodiment 4 and Embodiment 2 will be described. For other configurations excluding the configurations described later, since they are common to Embodiment 2, the same reference numerals as those in Embodiment 2 are assigned to the common configuration parts and the description thereof is omitted.

[0144] <Configuration of Relay Device 10> The relay device 10 in the fourth embodiment includes a device timer 27 similar to the third embodiment, in addition to the components included in the relay device 10 in the second embodiment.

[0145] <Configuration of in-vehicle device 13> The in-vehicle device 13 in the fourth embodiment includes a device timer 35, similar to the third embodiment, in addition to the components included in the in-vehicle device 13 in the second embodiment.

[0146] <Initial settings> 21 is a flowchart showing the procedure of the initial setting performed by the relay device 10 and the in-vehicle device 13 in the fourth embodiment. In the initial setting in the fourth embodiment, similar to the initial setting in the second embodiment, the device control unit 25 of the relay device 10 and the device control unit 33 of the in-vehicle device 13 each execute a data transmission process and an adjustment process. In the data transmission process in the fourth embodiment, steps S1 to S4 and S51 to S61 are executed similar to the second embodiment. In the adjustment process in the fourth embodiment, steps S11 to S16 and S71 to S73 are executed similar to the second embodiment.

[0147] In the adjustment process, the device control unit 33 of the in-vehicle device 13 executes step S73 and then reads out the device elapsed time measured by the device timer 35 (step S111). Next, the device control unit 33 instructs the device communication IC 31 to transmit device timer data indicating the device elapsed time read out in step S111 to the device communication IC 23 of the relay device 10 (step S112). After executing step S112, the device control unit 25 ends the data transmission process. If the in-vehicle device 13 is removed from the connection connector 10a, the device control unit 25 executes the data transmission process again.

[0148] In the data transmission process, after executing step S54, the device control unit 25 of the relay device 10 determines whether the device communication IC 23 has received the device timer data (step S101). If the device control unit 25 determines that the device communication IC 23 has not received the device timer data (S101: NO), it executes step S101 again and waits until the device communication IC 23 receives the device timer data.

[0149] When the device control unit 25 determines that the device communication IC 23 has received the device timer data (S101: YES), the device control unit 25 executes step S57. The device delay data and the device delay data in the fourth embodiment are the same as the device delay data and the device delay data in the third embodiment.

[0150] In step S58 of the data transmission process in the fourth embodiment, the device control unit 25 calculates device delay times and device delay times corresponding to the multiple data amounts indicated by the frame data, based on the device delay data and device delay data acquired in step S57. Each of the multiple device delay times calculated in step S58 also corresponds to the device elapsed time of the device timer 27. Each of the multiple device delay times calculated in step S58 also corresponds to the device elapsed time indicated by the device timer data. In step S59, the device control unit 25 calculates multiple overall periods based on the device delay times and device delay times calculated in step S58.

[0151] <Effects of Communication System 1> In step S60 of the data transmission process, the relay device 10 calculates not only the data amount of the data frame but also the device elapsed time and the equipment elapsed time, i.e., a plurality of accurate determination points that take into account aging degradation. Therefore, in step S61, the device control unit 25 appropriately adjusts the start point or length of the open period. The communication system 1 in the fourth embodiment achieves the same effects as the communication system 1 in the second embodiment.

[0152] <Modification of the fourth embodiment> After the in-vehicle device 13 is connected to the connector 10a, the device control unit 33 of the in-vehicle device 13 may execute steps S111 and S112 every time a predetermined period, for example, one year, elapses. In this case, the device control unit 25 of the relay device 10 executes steps S101 and S57 to S61.

[0153] <Modifications of the First to Fourth Embodiments> In the first to fourth embodiments, the device communication IC 23 has a processing element that executes processing. The device communication IC 23 may execute part of the above-mentioned processing executed by the device control unit 25 instead of the device control unit 25. In this case, both the device communication IC 23 and the device control unit 25, or the device communication IC 23 functions as a processing unit. Similarly, the device communication IC 31 has a processing element that executes processing. The device communication IC 31 may execute part or all of the above-mentioned processing executed by the device control unit 33 instead of the device control unit 33. In this case, both the device communication IC 31 and the device control unit 33, or the device communication IC 31 functions as a processing unit.

[0154] Each of the ECUs 11 and 12 and the in-vehicle device 13 may transmit a plurality of first data frames during an open period of the first queue Q1. Similarly, each of the ECUs 11 and 12 and the in-vehicle device 13 may transmit a plurality of second data frames during an open period of the second queue Q2. The process performed when the determination time falls within a closed period is not limited to discarding the data frames, but may also be to suspend transmission of the data frames. In this case, for example, the data frames are not transmitted until the next open period arrives. When the next open period arrives, the data frames whose transmission has been suspended are transmitted.

[0155] The number of queues provided in each of the transmission buffers T1, T2, T3 is not limited to 2 and may be 3 or more. The number of ECUs connected to the relay device 10 is not limited to 2 and may be 3 or more. The number of in-vehicle devices 13 connected to the relay device 10 may be 2 or more. The number of reception buffers and transmission buffers each matches the total number of ECUs and in-vehicle devices 13 connected to the relay device 10.

[0156] In the first and second embodiments, there is no problem if the device delay data indicates a device delay time corresponding to the data amount. Therefore, the content indicated by the device delay data is not limited to a function formula for calculating the device delay time based on the data amount, and may be, for example, a table indicating the relationship between the data amount and the device delay time. Similarly, there is no problem if the device delay data indicates a device delay time corresponding to the data amount. Therefore, the content indicated by the device delay data is not limited to a function formula for calculating the device delay time based on the data amount, and may be, for example, a table indicating the relationship between the data amount and the device delay time. If the data amount of the data frame transmitted by the in-vehicle device 13 is fixed, the device delay data may indicate a constant device delay time. In a similar case, the device delay data may indicate a constant device delay time.

[0157] In the third and fourth embodiments, there is no problem if the device delay data indicates a device delay time corresponding to the data amount and the device elapsed time. Therefore, the content indicated by the device delay data is not limited to a function formula for calculating the device delay time based on the data amount and the device delay time, and may be, for example, a table indicating the relationship between the data amount, the device delay time, and the device delay time. Similarly, there is no problem if the device delay data indicates a device delay time corresponding to the data amount and the device elapsed time. Therefore, the content indicated by the device delay data is not limited to a function formula for calculating the device delay time based on the data amount and the device elapsed time, and may be, for example, a table indicating the relationship between the data amount, the device elapsed time, and the device delay time.

[0158] The disclosed embodiments 1 to 4 are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0159] 1. Communication Systems 10. Repeater 10a Connector 11,12 ECU 13 In-vehicle equipment (communication equipment) 20 Master Counter 21,22 ECU communication IC 23 Device communication IC (receiver) 24 Device storage 25 Device control section (processing section) 26 Device Bus 27 Device Timer 30 Slave Counter 31 Equipment communication IC 31a Equipment Connector 32 Device storage section 33 Equipment control section (processing section) 34 Device Bus 35 Equipment Timer 36 Synchronous Timer Ae,Ar storage medium M Vehicle Pe,Pr Computer Program Q1 1st queue Q2 2nd queue R1, R2, R3 receive buffer T1, T2, T3 transmit buffer

Claims

1. A communication device mounted on a vehicle and transmitting data to a relay device that transmits the received data, comprising: A processing unit for executing a process, The processing unit includes: Instructing the relay device to transmit data; Obtain the transmission delay time from when the data transmission is instructed to when the data is transmitted, acquiring, from the relay device, a determination delay time from when the relay device receives data to when it is determined whether or not to transmit the received data; Calculate the entire period from when the data transmission is instructed to the time of the determination based on the acquired transmission delay time in the communication device and the determination delay time in the relay device. Communications equipment.

2. The permitted period during which the transmission of received data is permitted and the prohibited period during which the transmission of received data is prohibited are set alternately and repeatedly. The communication device according to claim 1 .

3. The processing unit determines a time point for instructing data transmission based on the calculated overall period. The communication device according to claim 2 .

4. The processing unit includes: Calculate the propagation time from when the data is sent to when the data is received, The total period is calculated based on the acquired transmission delay time and judgment delay time and the calculated propagation time. The communication device according to any one of claims 1 to 3.

5. The processing unit acquires a transmission delay time and a determination delay time associated with a data amount of data to be transmitted to the relay device. The communication device according to any one of claims 1 to 4.

6. A relay device mounted on a vehicle and transmitting data received from a communication device, comprising: A receiving unit for receiving data from the communication device; A processing unit for executing processing; Equipped with The processing unit includes: When the receiving unit receives data, the receiving unit determines whether or not to transmit the received data; acquiring, from the communication device, a transmission delay time from when the communication device is instructed to transmit data to when the data is transmitted; Acquire a determination delay time from when the receiving unit receives data to when it is determined whether or not to transmit the received data; Calculate the entire period from when the communication device is instructed to transmit data to when the determination is made based on the acquired transmission delay time in the communication device and the determination delay time in the relay device. Relay device.

7. an allowed period during which transmission of the data received by the receiving unit is permitted and an inhibited period during which transmission of the data received by the receiving unit is inhibited are set alternately and repeatedly; The processing unit determines to transmit the data received by the receiving unit when the determination time point falls within the permitted period. The relay device according to claim 6.

8. The processing unit includes: Calculating a determination time point for data received by the receiving unit based on the calculated overall period; The start time or length of the permission period is adjusted based on the calculated judgment time. The relay device according to claim 7.

9. A communication method for communicating data, comprising: acquiring a transmission delay time from when a communication device instructs a relay device to transmit the received data to when the data is transmitted; acquiring, from the relay device, a determination delay time from a time point when the relay device receives data to a time point when it is determined whether or not to transmit the received data; calculating an entire period from when a data transmission is instructed to the time of the determination based on the acquired transmission delay time in the communication device and the determined delay time in the relay device; The communication method is executed by a computer installed in a vehicle.

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