Communication systems and electronic control devices

Abstract

To provide a higher-speed on-vehicle network.SOLUTION: A communication system is a communication system for an on-vehicle comprises a plurality of ECU 1A to ECU 1F which are communicably connected each other. In the present communication system, a VID for determining a data path is allocated to each function. Each of the ECUs 1A to 1F comprises: a storage part 13 storing the VID allocated to each of a plurality of functions held by itself; and a communication part 11 that transmits data with the applied VID in accordance with the data to be transmitted. A GW 2 comprises a plurality of connection ports, holds a table that makes one or more VIDs correspond to each of the connection ports, and transmits the data from the connection port corresponding to the VID applied to the data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a communication system and an electronic control device. [Background technology]

[0002] Vehicles such as automobiles are equipped with communication systems that connect multiple electronic control units (ECUs). One of the communication protocols widely used in in-vehicle networks is the Control Area Network (CAN).

[0003] The amount of information transmitted over in-vehicle networks is increasing due to factors such as the increase in ECUs and the introduction of autonomous driving. This is leading to the expansion of existing standards and the use of faster Ethernet (registered trademark) for in-vehicle networks. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-118407 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a high-speed Ethernet is connected to an in-vehicle network, a data block is acquired from a high-speed frame received from the Ethernet, and the data block is transmitted to a low-speed communication line of the in-vehicle network. Although Patent Document 1 connects a high-speed Ethernet, it does not speed up the entire in-vehicle network.

[0006] In Ethernet communications, virtual local area networks (VLANs) are used to virtually divide the network into domains, separating traffic and reducing the amount of traffic flowing across the entire network, thereby increasing speed. Generally, VLANs are set based on switch ports, and Ethernet frames are only transferred to ports in the same VLAN.

[0007] Within the same VLAN, Ethernet frames can be transferred at Layer 2 (data link layer), but communication between VLANs requires data transfer at the higher layer, Layer 3 (network layer). Data transfer at higher layers increases the processing load and data delay, so relay devices require more powerful CPUs.

[0008] When applying a general Ethernet communication system to an in-vehicle communication system, it is conceivable to configure VLANs based on the physical domain to which the ECU belongs, such as infotainment, cluster, intelligent transport systems (ITS), etc. However, in-vehicle networks often involve communication between domains, and when the traffic volume between VLANs is high, delays in data transfer can occur, which has meant that ECUs such as central gateways that connect multiple ECUs need to be equipped with high-performance CPUs.

[0009] The present invention has been made in view of the above, and has an object to provide a faster in-vehicle network. [Means for solving the problem]

[0010] A communication system according to one aspect of the present invention is an in-vehicle communication system including a plurality of electronic control units connected to each other for communication. In this communication system, an identifier for determining a data path is assigned to each function. Each electronic control unit stores the identifier assigned to each of its own functions, and transmits data with an identifier corresponding to the data to be transmitted. [Effects of the Invention]

[0011] According to the present invention, a faster in-vehicle network can be provided. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an overall configuration diagram for explaining an outline of a communication system according to this embodiment. [Figure 2] FIG. 2 is a functional block diagram showing an example of the configuration of the electronic control unit. [Figure 3] FIG. 3 is a diagram showing an example of a table in which functions held by an electronic control unit are associated with VIDs. [Figure 4] FIG. 4 is a functional block diagram illustrating an example of the configuration of a gateway. [Figure 5] FIG. 5 is a diagram showing an example of a table in which port numbers and VIDs are associated with each other and stored in the gateway. [Figure 6] FIG. 6 is a flowchart showing an example of a process flow in which the electronic control unit transmits data. [Figure 7] FIG. 7 is a flowchart showing an example of the flow of a process in which the gateway transfers data. [Figure 8] FIG. 8 is a diagram showing an example in which the layout of the electronic control unit is changed. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0014] A communication system according to this embodiment will be described with reference to FIG. 1. The communication system shown in FIG. 1 is an in-vehicle communication system and includes electronic control units (ECUs) 1A-1F and a gateway (GW) 2. The ECUs 1A-1F and GW2 are connected by communication lines. The ECUs 1A and 1B are in-vehicle ECUs that belong to the chassis domain, the ECU 1C is an engine domain, and the ECUs 1D, 1E, and 1F are ITS domain ECUs. Each of the ECUs 1A-1F has the function of electronically controlling the systems of the respective domains. The GW2 has multiple connection ports for connecting communication lines and has the function of relaying data transmitted and received between the ECUs 1A-1F. The GW2 is also a type of ECU. Like the ECU 1D, an ECU may have multiple connection ports and relay data. Note that FIG. 1 is an example for explaining the communication system, and although six ECUs and one GW are shown, the present invention is not limited to this.

[0015] ECU1A-1F and GW2 communicate by sending and receiving Ethernet frames with VLAN tags. The VLAN tag contains a VLAN Identifier (VID) and a Priority Code Point (PCP) and is added to the header of the Ethernet frame. The VID is an identifier that specifies the VLAN. The PCP is a field that specifies the priority. The VLAN tag also contains other information, but its explanation is omitted here.

[0016] In the communication system of this embodiment, logical groups of the network are formed based on functions rather than domains, and each ECU belongs to one or more logical groups according to its functions. A logical group is also called a VLAN. An ECU with multiple functions is assigned multiple IP addresses for each function, and a corresponding VID is assigned to each IP address. For example, in the example of FIG. 1, VID=100 is assigned to diagnostic functions, VID=400 to control functions, VID=800 to human-machine interface (HMI) functions, and VID=930 to special control applications, forming logical groups for each function based on VIDs. ECUs 1A, 1B, 1C, 1D, and GW2 belong to the diagnostic group. ECUs 1D, 1E, and 1F belong to the control group. ECUs 1A and 1C belong to the HMI group. ECUs 1D and 1F belong to the special control application group. ECUs 1A, 1C, 1D, and 1F belong to multiple logical groups.

[0017] In the communication system of this embodiment, a VID may be assigned to each data type, and a VLAN may be formed for each data type, or a VID may be assigned to each application that uses the data, and a VLAN may be formed for each application. When forming a VLAN, a VLAN may be formed for each function, and then a VLAN may be formed for each data type and application. Functions are classified at a relatively large granularity, such as image, sensor, and diagnosis. Data types and applications are classified at a smaller granularity, such as images captured by a camera and images used in a navigation system, among image-related functions. Forming a VLAN at a smaller granularity narrows the broadcast range, thereby reducing the amount of traffic flowing throughout the communication system.

[0018] GW2 is equipped with a transfer unit 21 having multiple connection ports and connects multiple ECUs. GW2 determines a data path based on a VLAN tag attached to an Ethernet frame and transfers the Ethernet frame at Layer 2. Even if data is transmitted and received between different domains, such as between ECU1A and ECU1C in FIG. 1, ECU1A and ECU1C belong to the same logical group (VID=100 or VID=800), so GW2 transfers data between ECU1A and ECU1C at Layer 2 according to the VLAN tag. Note that ECU1D, which is equipped with a transfer unit 21 having multiple connection ports, also transfers data transmitted and received between ECUs at Layer 2 according to the VLAN tag, just like GW2.

[0019] Next, the configuration of the ECU 1 will be described with reference to Fig. 2. When there is no need to distinguish between the ECUs 1A to 1F, they will be referred to as ECU 1.

[0020] The ECU 1 shown in FIG. 2 includes a communication unit 11, a control unit 12, and a storage unit 13.

[0021] The communication unit 11 has a connection port for connecting a communication line, and transmits data by assigning a VLAN tag corresponding to the data to be transmitted, and receives data from another ECU 1 or GW 2. The communication unit 11 may have multiple connection ports and be connected to multiple ECUs 1 and GW 2. The communication unit 11 sets the IP address assigned to the ECU 1 as the source IP address in the IP header and assigns a VLAN tag including a VID assigned to the IP address to the Ethernet header. The communication unit 11 may set a priority to the PCP in the VAL tag. If multiple IP addresses are assigned to the ECU 1, the communication unit 11 sets an IP address corresponding to the data in the IP header and assigns a VLAN tag including a VID assigned to the IP address to the Ethernet header. For example, the ECU 1A in FIG. 1 belongs to a diagnostic system group and an HMI system group. When ECU 1A transmits data related to diagnostic functions, communication unit 11 sets the IP address assigned with VID=100 of the diagnostic group as the source IP address of the IP header, and adds a VLAN tag including VID=100 of the diagnostic group to the Ethernet header. When ECU 1A transmits data related to HMI functions, communication unit 11 sets the IP address assigned with VID=800 of the HMI group as the source IP address of the IP header, and adds a VLAN tag including VID=800 of the HMI group to the Ethernet header.

[0022] The control unit 12 electronically controls the system of the domain to which the ECU 1 belongs. The control unit 12 transmits and receives data to and from other ECUs 1 when electronically controlling the system.

[0023] The storage unit 13 stores a VID assigned to each function of the ECU 1. FIG. 3 shows an example of a table held in the storage unit 13 of the ECU 1A. The ECU 1A has diagnostic functions and HMI functions, with VID=100 assigned to the diagnostic group and VID=800 assigned to the HMI group. The table may also include IP addresses corresponding to the functions. The communication unit 11 refers to the storage unit 13 and assigns VID=100 to data related to diagnostic functions and VID=800 to data related to HMI functions.

[0024] Next, the configuration of the GW2 will be described with reference to FIG.

[0025] The GW 2 shown in FIG. 4 includes a transfer unit 21, a control unit 22, and a storage unit 23.

[0026] The transfer unit 21 has a plurality of connection ports and is connected to a plurality of ECUs 1, and transfers Ethernet frames at Layer 2 based on the VLAN tags attached to the Ethernet frames.

[0027] The control unit 22 controls the GW 2 itself. If the GW 2 has a diagnostic function, the control unit 22 executes the diagnosis and transmits data including the diagnosis result.

[0028] The storage unit 23 holds a table that associates VIDs with connection ports. FIG. 5 shows an example of the table held by the storage unit 23 of the GW2. The GW2 is assumed to have connection ports numbered 1 to 5. In the table of FIG. 5, each connection port is associated with a VID assigned to the connected ECU1. In the example of FIG. 1, VID=100,800 is assigned to ECU1A and ECU1C, VID=100 is assigned to ECU1B, and VID=100,400,930 is assigned to ECU1D. The first connection port is connected to ECU1A, the second connection port is connected to ECU1B, the third connection port is connected to ECU1C, and the fourth connection port is connected to ECU1D. The fifth connection port is connected to the control unit 22 of the GW2 itself. The control unit 22 has a diagnostic function. Therefore, in the table of FIG. 5, connection port 1 is associated with VID=100,800, connection port 2 is associated with VID=100, connection port 3 is associated with VID=100,800, connection port 4 is associated with VID=100,400,930, and connection port 5 is associated with VID=100.

[0029] The transfer unit 21 refers to the table held in the storage unit 23, and transmits the data from the connection port associated with the VID assigned to the received data. For example, when data with VID=100 is received from connection port 1, the transfer unit 21 transmits the data from connection ports 2 to 5.

[0030] The transfer unit 21 may learn the MAC address of the sender, update the MAC address table, and determine a connection port from which data is to be sent based on the MAC address table. For example, when the transfer unit 21 receives data (Ethernet frame) from a certain connection port, it updates the MAC address table by associating the MAC address of the sender in the header of the received Ethernet frame with the connection port. When the transfer unit 21 receives data, it refers to the MAC address table to identify the connection port to which the MAC address of the destination of the received data is associated, and sends the data from that connection port. A VID and a MAC address may be associated with the connection port in the table of FIG. 5. Note that a MAC address registered in the MAC address table is deleted from the MAC address table if no Ethernet frame with that MAC address as the sender is received for a predetermined period of time. If the destination MAC address is not registered in the MAC address table, the transfer unit 21 determines a connection port from which data is to be sent based on the VID.

[0031] Each unit of the ECU1 and GW2 may be configured by a computer equipped with an arithmetic processing unit, a storage device, etc., and the processing of each unit may be executed by a program. This program is stored in the storage device equipped in the ECU1 and GW2, and can also be recorded on a recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, or provided via a network.

[0032] Next, the process in which the ECU 1 transmits data will be described with reference to the flowchart of FIG.

[0033] In step S11, the ECU 1 sets the IP address of the ECP 1 to which the data is to be sent as the destination IP address in the IP header, and also sets an IP address according to the data as the source IP address in the IP header.

[0034] In step S12, the ECU 1 assigns a VLAN tag according to the data. For example, in the example of Fig. 1, even if the communication is between the same ECU 1A and ECU 1C, if the data relates to a diagnostic function, a VLAN tag of VID=100 is assigned, and if the data relates to an HMI function, a VLAN tag of VID=800 is assigned. The ECU 1 may set a priority to the PCP of the VLAN tag.

[0035] In step S13, the ECU 1 sends the data with the VLAN tag attached from the connection port.

[0036] The data sent from the ECU1 is transferred by the GW2.

[0037] Next, the process of transferring data by the GW2 will be described with reference to the flowchart of FIG.

[0038] In step S21, the GW2 receives data from the ECU1.

[0039] In step S22, GW2 sends the data based on the VLAN tag of the received data. GW2 may also send the data based on the MAC address of the destination. In either case, the data is transferred at layer 2.

[0040] Next, the ECU routing change will be described with reference to FIG.

[0041] In Figure 8, the connection ports through which ECU1B and ECU1C connect to GW2 in Figure 1 have been swapped. Specifically, the state where ECU1B was connected to connection port number 2 of GW2 and ECU1C was connected to connection port number 3 has been changed to the state where ECU1C is connected to connection port number 2 and ECU1B is connected to connection port number 3.

[0042] In the communication system of this embodiment, VIDs are not set based on physical connections such as connection ports, but are set based on functions. Therefore, even if the connection port of ECU1 is changed, there is no need to change the settings of ECU1; only the settings of GW2 need to be changed. In the example of Figure 8, the association between connection ports 2 and 3 and VIDs in the table held by GW2 is changed. VID = 100,800 is associated with connection port 2, and VID = 100 is associated with connection port 3. Since data is basically transferred at Layer 2, there is no need to change the settings of ECU1B and ECU1C.

[0043] As described above, the communication system of this embodiment provides the following advantages.

[0044] A VID for determining the data path is assigned to each function of ECUs 1A to 1F, and a VLAN is formed for each function. Each of ECUs 1A to 1F includes a storage unit 13 that stores the VIDs assigned to each of its own functions, and a communication unit 11 that assigns a VID corresponding to the data to be transmitted and transmits the data. This allows data to be transmitted between ECUs 1A to 1F within the VLANs divided by function, regardless of the domain to which ECUs 1A to 1F belong, thereby improving data transfer performance. This brings various benefits to improving autonomous driving performance, which requires processing large amounts of data.

[0045] GW2 has multiple connection ports, maintains a table in which each connection port corresponds to one or more VIDs, and sends data from the connection port corresponding to the VID assigned to the data, thereby enabling efficient transfer of data with assigned VIDs in the communication system. [Explanation of symbols]

[0046] 1, 1A to 1F...Electronic control unit 11. Communications Department 12...Control unit 13...Storage section 2. Gateway 21...Transfer section 22...Control unit 23...Storage section

Claims

1. An in-vehicle communication system comprising a plurality of electronic control units connected to each other so as to be able to communicate with each other, Each function is assigned an identifier to determine the data path. The identifier is assigned to each type of data to be transmitted and each application that uses the data in addition to the function, Each of the electronic control devices is a storage unit that stores the identifiers assigned to each of a plurality of functions of the electronic control device; a communication unit that assigns an identifier corresponding to the data to be transmitted and transmits the data; A communication system comprising:

2. 2. The communication system of claim 1, Among the plurality of electronic control devices, the electronic control device having a relay function and including a plurality of connection ports for connecting the electronic control devices with communication lines holds a table in which one or more of the identifiers correspond to each of the connection ports, and transmits the data from the connection port corresponding to the identifier assigned to the data. Communication system.

3. An electronic control device constituting an in-vehicle communication system, Each function is assigned an identifier to determine the data path. The identifier is assigned to each type of data to be transmitted and each application that uses the data in addition to the function, a storage unit that stores the identifiers assigned to each of a plurality of functions of the electronic control device; A communication unit that assigns an identifier corresponding to the data to be transmitted and transmits the data. Electronic control unit.

4. 4. The electronic control device according to claim 3, a plurality of connection ports for connecting the electronic control devices with communication lines; maintaining a table in which one or more of the identifiers are associated with each of the connection ports; The communication unit transmits the data from the connection port corresponding to the identifier assigned to the data. Electronic control unit.

5. A communication system according to claim 1, Among the plurality of electronic control devices, an electronic control device having a relay function and including a plurality of connection ports for connecting the electronic control devices with communication lines refers to a MAC address table in which the MAC address of the electronic control device that is the sender of past data received in the past is associated with the connection port that received the past data, identifies the connection port associated with the MAC address of the destination of newly received new data, and transmits the new data from the identified connection port. Communication system.

6. 4. The electronic control device according to claim 3, Among the plurality of electronic control devices, an electronic control device having a relay function and including a plurality of connection ports for connecting the electronic control devices with communication lines refers to a MAC address table in which the MAC address of the electronic control device that is the sender of past data received in the past is associated with the connection port that received the past data, identifies the connection port associated with the MAC address of the destination of newly received new data, and transmits the new data from the identified connection port. Electronic control unit.

7. 6. A communication system according to claim 1 or 5, A MAC address table is updated in which the MAC address of the electronic control device that is the sender of the past data received in the past is associated with the connection port that is a connection port for connecting the electronic control devices via a communication line and that received the past data, to associate the past data received within a predetermined time from the present, and the connection port associated with the MAC address of the destination of newly received new data is identified by referring to the MAC address table, and the new data is sent from the identified connection port. Communication system.

8. 7. The electronic control device according to claim 3 or 6, A MAC address table is updated in which the MAC address of the electronic control device that is the sender of the past data received in the past is associated with the connection port that is a connection port for connecting the electronic control devices via a communication line and that received the past data, to associate the past data received within a predetermined time from the present, and the connection port associated with the MAC address of the destination of newly received new data is identified by referring to the MAC address table, and the new data is sent from the identified connection port. Electronic control unit.

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