CAN communication method and motor vehicle

Abstract

To transfer data between a plurality of electronic control units and a diagnosis device using a CAN ID allocated to one electronic control unit without increasing a load of hardware or an operation load of the electronic control units.SOLUTION: An automatic vehicle 100 includes first to third electronic control units 51-53 mounted thereon. A CAN ID for CAN communication with an externally connected diagnosis device 200 is set to the first electronic control unit 51. Different data IDs are set to the second and third electronic control units 52, 53, respectively. The second and third electronic control unit 52, 53 are configured to transfer data to / from the diagnosis device 200, using the data IDs thereof, via the first electronic control unit 51, under the CAN ID of the first electronic control unit 51, and to secure CAN communication between the second and third electronic control units 52, 53 and the diagnosis device 200 together with the first electronic control unit 51.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fault diagnosis device for diagnosing the operation of an automotive vehicle and a CAN communication method between the automotive vehicle, and in particular to a method for reducing the load on hardware and software resources. [Background technology]

[0002] It is well known that in operational diagnosis of an automobile vehicle, a diagnostic device is used that exchanges various data with an electronic control unit installed in the vehicle via a CAN (Controller Area Network) and performs operational analysis based on the data acquired from the electronic control unit (see, for example, Patent Document 1, etc.). CAN communication between such a diagnostic device and an electronic control unit requires an identification code called a CAN ID to mutually identify the communication targets. Normally, CAN communication between a diagnostic device and an electronic control unit requires the setting of a pair of IDs consisting of a sender ID required for transmission from the diagnostic device to the electronic control unit and a receiver ID required for responses from the electronic control unit to the diagnostic device. Therefore, in order to enable CAN communication with multiple electronic control units installed in a motor vehicle using such a diagnostic device, transmitting and receiving IDs corresponding to the number of installed electronic control units are required. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-301997 Summary of the Invention [Problem to be solved by the invention]

[0004] However, depending on the CAN configuration, there may be restrictions on the number of IDs that can be set in order to enhance security, or there may be restrictions on the number of IDs that can be set due to the specifications of the diagnostic device, etc. In such cases, there may be electronic control units that are not subject to diagnosis by the diagnostic device. One way to solve this problem is to have one electronic control unit, to which an ID is assigned, handle communication between the other electronic control units and the diagnostic device, as will be described below.

[0005] That is, first, the electronic control unit to which the ID is set is configured to have a storage area secured that is necessary for storing and holding data when data is exchanged between the other multiple electronic control units and the diagnostic device. With this configuration, data transmitted from the diagnostic device to the other multiple electronic control units is temporarily stored and held in the above-mentioned storage area and transmitted to the corresponding electronic control unit at an appropriate timing, while data transmitted from the other multiple electronic control units to the diagnostic device is temporarily stored and held in the above-mentioned storage area and transmitted to the diagnostic device at an appropriate timing.

[0006] While this method does enable communication between multiple electronic control units and a diagnostic device using a single ID, the electronic control unit to which the ID is assigned must be configured with a storage area corresponding to the number of other electronic control units. This increases the burden on the hardware and increases the operating load on the electronic control unit to which the ID is assigned, resulting in problems such as reduced operating efficiency.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and provides a CAN communication method and an automotive vehicle that enable data exchange between multiple electronic control units and a diagnostic device using a CAN ID assigned to one electronic control unit, without increasing the burden on hardware or the operational load of the electronic control unit. [Means for solving the problem]

[0008] In order to achieve the above object of the present invention, a CAN communication method according to the present invention comprises: Installed in a motor vehicle Complex A number of electronic control units and a diagnostic device externally connected to the vehicle; Data from the disconnecting device Sending and receiving A CAN communication method that enables The plurality of electronic control units are configured to be able to communicate with the diagnostic device via a CAN, and include one specific electronic control unit to which a CAN ID for CAN communication is set, and the CAN communication method includes: a data ID configuring a message in CAN communication between the specific electronic control unit and the diagnostic device is set separately for each of the plurality of electronic control units excluding the specific electronic control unit; Each of the plurality of electronic control units excluding the specific electronic control unit is via the specific electronic control unit , the specific electronic control unit Under the CAN ID, the required data for each data ID is Sending and receiving By carrying out the above with the diagnostic device, CAN communication between the plurality of electronic control units and the diagnostic device is substantially possible. In order to achieve the above object of the present invention, the motor vehicle according to the present invention comprises: Equipped with multiple electronic control units by myself A moving vehicle, The plurality of electronic control units include one specific electronic control unit configured to be able to communicate with an externally connected diagnostic device via a CAN, and having a CAN ID set for the CAN communication; Each of the plurality of electronic control units excluding the specific electronic control unit to a data ID constituting a message in CAN communication between the specific electronic control unit and the diagnostic device is set separately; Each of the plurality of electronic control units excluding the specific electronic control unit is via the specific electronic control unit , the specific electronic control unit Under the CAN ID, the diagnostic device and each data ID to Required data By sending and receiving CAN communication is substantially possible between the plurality of electronic control units and the diagnostic device. [Effects of the Invention]

[0009] According to the present invention, a configuration is provided in which CAN communication between other electronic control units and a diagnostic device is substantially possible via a specific electronic control unit using the CAN ID of the specific electronic control unit, thereby achieving the effect of enabling a diagnostic device to obtain diagnostic data for multiple electronic control units using a single CAN ID without increasing the burden on hardware or the operational load on the specific electronic control unit. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a configuration diagram showing a connection state between a diagnostic device in which CAN communication is performed and an electronic control unit of an automotive vehicle according to an embodiment of the present invention. [Figure 2] 2 is a flowchart illustrating a CAN communication processing procedure between the diagnostic device and a plurality of electronic control units in the configuration shown in FIG. 1. [Figure 3] FIG. 3 is an explanatory diagram illustrating an example of data transmitted and received between the diagnostic device and a plurality of electronic control units. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The components, arrangements, etc. described below do not limit the present invention, and various modifications can be made within the scope of the present invention. First, an example of the connection configuration between an automobile vehicle and a diagnostic device according to an embodiment of the present invention will be described with reference to FIG. First, the diagnostic device (denoted as "DIA" in FIG. 1) 200 is not specific to the present invention, but has a well-known conventional configuration configured to be able to acquire diagnostic data related to the operation of a motor vehicle via a CAN. Therefore, diagnostic device 200 is capable of diagnostic communication via CAN communication, and is assumed to have a configuration that satisfies, for example, a network layer for diagnostic communication based on ISO 15765 and an application layer based on ISO 14229-1.

[0012] This diagnostic device 200 is externally connected to an automobile vehicle (hereinafter referred to as "vehicle") 100 using a connection cable (not shown), thereby enabling CAN communication with an electronic control unit mounted on the vehicle 100 as described below. First, the vehicle 100 in the embodiment of the present invention is assumed to be equipped with a plurality of electronic control units, and the configuration example shown in FIG. 1 shows a configuration in which three first to third electronic control units (represented as "ECU1," "ECU2," and "ECU3" in FIG. 1) 51 to 53 are equipped.

[0013] The first to third electronic control units 51 to 53 are configured, for example, with a microcomputer (not shown) having a known and commonly-known configuration as the core, and with memory elements such as RAM and ROM (not shown), and an interface circuit (not shown) for interfacing with an external electronic circuit (not shown), etc. as main components.

[0014] These first to third electronic control units 51 to 53 are typified by, for example, an engine control unit, a transmission control unit, an airbag control unit, etc., but they do not need to be limited to a specific control unit, and may be any unit capable of performing CAN communication as described below.

[0015] In the embodiment of the present invention, a first electronic control unit (specific electronic control unit) 51 is connected to a diagnostic device 200 via a CAN main bus 1, and mutual CAN communication is possible. That is, in the embodiment of the present invention, it is assumed that the CAN ID required for CAN communication with diagnostic device 200 is set only for first electronic control unit 51.

[0016] The first to third electronic control units 51 to 53 are interconnected by a CAN sub-bus 2, enabling CAN communication. The second and third electronic control units 52, 53 are capable of CAN communication only with the first electronic control unit 51 via the CAN sub-bus 2, but because CAN IDs are not set for the second and third electronic control units 52, 53, they are not able to perform direct CAN communication with the diagnostic device 200.

[0017] Next, with reference to the flowchart shown in FIG. 2 and the example messages shown in FIG. 3, the diagnostic communication based on the CAN communication performed between the diagnostic device 200 and the first to third electronic control units 51 to 53 will be described. First, the flowchart in FIG. 2 shows the procedure for data exchange between the diagnostic device 200 and the first to third electronic control units 51 to 53. The left side of the center of the figure shows the processing procedure in the first electronic control unit 51, and the right side of the center of the figure shows the processing procedure in the second and third electronic control units 52 and 53. It should be noted that, as a matter of course, it is assumed that the diagnostic device 200 and the first to third electronic control units 51 to 53 in the embodiment of the present invention are each capable of executing a diagnostic communication protocol based on CAN communication.

[0018] FIG. 3 is an explanatory diagram illustrating examples of CAN messages exchanged in CAN communications between the diagnostic device 200 and the first electronic control unit 51, and between the first electronic control unit 51 and the second and third electronic control units 52 and 53. In FIG. 3, the numbers in parentheses indicate the order in which CAN messages are transmitted and received between the diagnostic device 200 and the first to third electronic control units 51 to 53 in ascending order. As mentioned above, the diagnostic device 200 and the first to third electronic control units 51 to 53 are configured to execute a diagnostic communication protocol based on CAN communication, and the CAN messages exchanged between them are based on that protocol.

[0019] These CAN messages are broadly divided into request messages sent from the diagnostic device 200 and response messages sent from the first electronic control unit 51 to the diagnostic device 200. In either case, a single message is basically composed of a CAN ID, a service ID, and a data ID, in that order, just like in the past. As in the past, a set of CAN IDs consists of two IDs: an ID for identifying an electronic control unit when a request message is sent from diagnostic device 200 to the electronic control unit (hereinafter, for convenience of explanation, referred to as a "request CAN ID"), and an ID used when a response message is sent from the identified electronic control unit to diagnostic device 200 (hereinafter, for convenience of explanation, referred to as a "response CAN ID"). In FIG. 1, for convenience, the request CAN ID is represented as "ID1-Tx" and the response CAN ID is represented as "ID2-Rx."

[0020] The service ID is an ID that indicates the outline of the diagnostic service that diagnostic device 200 requests from the electronic control unit, as in the conventional case. The data ID is an ID that identifies the target of the diagnostic service identified by the service ID. This data ID itself is basically the same as in the past, but in the embodiment of the present invention, as will be described later, it is used in a way that essentially enables diagnostic communication between diagnostic device 200 and multiple electronic control units under a single CAN ID.

[0021] The flow of processing by the diagnostic device 200 and the first to third electronic control units 51 to 53 in the example of the diagnostic communication message shown in FIG. 3 will be described below with reference to the flowchart shown in FIG. In this example, it is assumed that $700 is set as the request CAN ID and $701 is set as the response CAN ID between the diagnostic device 200 and the first electronic control unit 51. Also, assume that the first electronic control unit 51 is set with a data ID of $1000, the second electronic control unit 52 is set with a data ID of $5000, and the third electronic control unit 53 is set with a data ID of $A000. In addition, in FIG. 3, "Tool" refers to the diagnostic device 200, "ECU1" refers to the first electronic control unit 51, "ECU2" refers to the second electronic control unit 52, and "ECU3" refers to the third electronic control unit 53, respectively. Furthermore, SID stands for service ID, and DID stands for data ID.

[0022] FIG. 3(1) is an example of a request message that is first transmitted from the diagnostic device 200 to the first electronic control unit 51. Here, as mentioned above, SID$22 specifies the content of the diagnostic service that diagnostic device 200 requests from the electronic control unit. However, the specific diagnostic service assigned to each service ID varies depending on the specifications of diagnostic device 200, and is not limited to a specific content but can be set arbitrarily. DID$1000 means that the target area of ​​the diagnostic service specified by SID$22 is $1000. In this example, DID$1000 indicates the area in which diagnostic data obtained as a result of executing the diagnostic service specified by SID$22 in the first electronic control unit 51 is acquired.

[0023] In response to the above-mentioned request message from the diagnostic device 200, the first electronic control unit 51 returns a response message as shown in FIG. Here, first, SID$62 in the response message of the first electronic control unit 51 indicates that the diagnostic data (described later) transmitted from this first electronic control unit 51 to the diagnostic device 200 corresponds to SID$22 in the request message transmitted from the diagnostic device 200. The diagnostic data corresponding to SID$62 is arranged after the data ID as shown in FIG. 3(2) and is transmitted to diagnostic device 200. In FIG. 3(2), the diagnostic data is denoted as "xx" for convenience.

[0024] On the other hand, since the request message from the previous diagnostic device 200 is directed to the first electronic control unit 51 as described above, no response messages are sent from the second and third electronic control units 52, 53 to the diagnostic device 200. Here, the flow of a series of processes in the first to third electronic control units 51 to 53 in response to a request message from the diagnostic device 200 shown in FIG. 3(1) will be described below with reference to FIG.

[0025] The request message sent from the diagnostic device 200 is stored in an appropriate memory area in the first electronic control unit 51 as a command reception, and is also transferred (command sub-bus transfer) to the second and third electronic control units 52 and 53 via the CAN sub-bus 2 (see step S110 in Figure 2). In the first electronic control unit 51, it is determined whether there are any other electronic control units that match the received service ID and data ID (see step S120 in Figure 2), and if it is determined that there are no other matching electronic control units (YES), it is determined whether the received service ID and data ID correspond to the first electronic control unit 51 (see step S130 in Figure 2).

[0026] On the other hand, if the determination result in step S120 is NO, that is, if it is determined that there is another electronic control unit that matches the received service ID and data ID, a response will be made by the other electronic control unit, as will be described later. In this case, no special processing by the first electronic control unit 51 is required, and the first electronic control unit 51 enters a standby state, waiting for the processing of step S160, which will be described later.

[0027] In step S130, if it is determined that the received service ID and data ID correspond to the IDs set in the first electronic control unit 51 (YES), the required response is output (see step S140 in FIG. 2). That is, the response message as shown in FIG. 3(2) is transmitted from the first electronic control unit 51 to the diagnostic device 200.

[0028] On the other hand, if it is determined in step S130 that the received service ID and data ID do not correspond to the IDs set in the first electronic control unit 51 (NO), a predetermined response message (negative response) indicating that there is no electronic control unit corresponding to the request message is sent to the diagnostic device 200 (see step S150 in FIG. 2).

[0029] On the other hand, in the second and third electronic control units 52 and 53 to which the request message shown in FIG. 3(1) is transferred from the first electronic control unit 51 via the CAN sub-bus 2, the following processing is executed. That is, the second electronic control unit 52 and the third electronic control unit 53 each determine whether the transferred request message is relevant (see steps S210 and S230 in FIG. 2).

[0030] Since the request message shown in Figure 3(1) is addressed to the first electronic control unit 51, both the second and third electronic control units 52 and 53 determine that the transferred service ID and data ID do not correspond to the IDs set in each electronic control unit. In this case, the second and third electronic control units 52, 53 maintain a non-response state in which they do not transmit any particular response message (see step S250 in FIG. 2). Note that in FIG. 3(2), the non-response state described above is described as "No response."

[0031] On the other hand, after receiving the response message (see FIG. 3(2)) from the first electronic control unit 51, the diagnostic device 200 transmits a request message to the second electronic control unit 52 under the request CAN ID of the first electronic control unit 51, as shown in FIG. 3(3).

[0032] In FIG. 3(3), $700 is the request CAN ID for the first electronic control unit 51 as described above. In addition, in FIG. 3(3), SID$22 is as described above, so a repeated explanation will be omitted here. Furthermore, in FIG. 3(3), DID$5000 is a data ID preset for the second electronic control unit 52.

[0033] The request message shown in Figure 3(3) is first received by the first electronic control unit 51, and then transferred by the first electronic control unit 51 to the second and third electronic control units 52, 53 via the CAN sub-bus 2. In this case, since the request message is directed to the second electronic control unit 52 as described above, the first electronic control unit 51 goes into a standby state as described above (see step S120 in FIG. 2).

[0034] Moreover, the third electronic control unit 53 determines that the data ID does not correspond to the preset one (see step S230 in FIG. 2), and enters a non-response state (see step S250 in FIG. 2). On the other hand, in the second electronic control unit 52, it is determined that the service ID and data ID match (see step S210 in FIG. 2), and the required response is output (see step S220 in FIG. 2). That is, a response message such as that shown in FIG. 3(4) is transmitted from the second electronic control unit 52 to the CAN sub-bus 2, and then transferred to the CAN main bus 1 in the first electronic control unit 51 (see step S160 in FIG. 2), and then received and processed in the diagnostic device 200 in the same way as data exchange with the first electronic control unit 51 (see step S170 in FIG. 2).

[0035] In the response message shown in FIG. 3(4), SID$62 indicates that the data transmitted by this response message corresponds to SID$22 transmitted from diagnostic device 200. The diagnostic data corresponding to SID$62 is arranged after the data ID as shown in FIG. 3(4) and is transmitted to diagnostic device 200. In FIG. 3(4), the diagnostic data is denoted as "yy" for convenience.

[0036] Next, after receiving the response message (see FIG. 3(4)) from the second electronic control unit 52 via the first electronic control unit 51 as described above, the diagnostic device 200 transmits a request message to the third electronic control unit 53 as shown in FIG. 3(5) under the request CAN ID of the first electronic control unit 51.

[0037] In FIG. 3(5), $700 is the request CAN ID for the first electronic control unit 51 as described above. In addition, in FIG. 3(5), SID$22 is as described above, so a repeated explanation will be omitted here. Furthermore, in FIG. 3(5), DID$A000 is a data ID preset for the third electronic control unit 53. The request message shown in Figure 3(5) is received by the first electronic control unit 51, as in the case of Figure 3(3), and then forwarded by the first electronic control unit 51 to the second and third electronic control units 52, 53 via the CAN sub-bus 2.

[0038] In this case, since the request message is addressed to the third electronic control unit 53 as described above, the first electronic control unit 51 goes into a standby state as described above (see step S120 in FIG. 2). Further, the second electronic control unit 52 determines that the data ID does not correspond to the preset one (see step S210 in FIG. 2), and goes into a non-response state (see step S250 in FIG. 2).

[0039] On the other hand, in the third electronic control unit 53, it is determined that the service ID and data ID match (see step S230 in FIG. 2), and the required response is output (see step S240 in FIG. 2). That is, a response message such as that shown in FIG. 3(6) is transmitted from the third electronic control unit 53 to the CAN sub-bus 2, and then transferred to the CAN main bus 1 in the first electronic control unit 51 (see step S160 in FIG. 2), and in the diagnostic device 200, reception is processed in the same way as data exchange with the first electronic control unit 51 (see step S170 in FIG. 2).

[0040] In the response message shown in FIG. 3(6), SID$62 indicates that the data transmitted by this response message corresponds to SID$22 transmitted from diagnostic device 200. The diagnostic data corresponding to SID$62 is arranged after the data ID as shown in FIG. 3(6) and is transmitted to diagnostic device 200. In FIG. 3(6), the diagnostic data is denoted as "zz" for convenience.

[0041] Next, a processing procedure in the first to third electronic control units 51 to 53 when the data ID in the request message from the diagnostic device 200 does not correspond to any of the electronic control units will be described. Figure 3(7) shows an example in which DID$2000 is included in the request message as a data ID other than the data IDs set in the first to third electronic control units 51 to 53. Note that $700 and SID$22 are as explained in Figure 3(1).

[0042] In this case, the first electronic control unit 51 outputs a negative response indicating that the corresponding electronic control unit does not exist, as shown in FIG. 3(8) (see step S150 in FIG. 2). In FIG. 3(8), the "Negative response" part actually uses a predetermined code or the like as a negative response. Furthermore, the second and third electronic control units 52 and 53 are in a non-responsive state because the data ID does not match (see step S250 in FIG. 2).

[0043] In the above-described embodiment of the present invention, an example configuration in which three electronic control units are installed in a vehicle and there is one CAN ID has been described. However, the number of electronic control units does not have to be limited to three, and by appropriately assigning data IDs, even if there is a configuration with a desired number of electronic control units, it is possible to obtain diagnostic data for multiple electronic control units under one CAN ID, just as in the embodiment of the present invention. [Industrial Applicability]

[0044] This can be applied to automobiles where it is desired to exchange data between multiple electronic control units and a diagnostic device using a CAN ID assigned to one electronic control unit, without increasing the burden on hardware or the operational load of the electronic control unit. [Explanation of symbols]

[0045] 1...CAN main bus 2...CAN sub-bus 51...First electronic control unit 52...Second electronic control unit 53...Third electronic control unit 200...Diagnostic equipment

Claims

1. A CAN communication method that enables data transmission and reception between a plurality of electronic control units mounted on a vehicle and a diagnostic device externally connected to the vehicle, comprising: the plurality of electronic control units include one specific electronic control unit configured to be able to communicate with the diagnostic device via CAN and having a CAN ID set for the CAN communication; The CAN communication method includes: a data ID for configuring a message in CAN communication between the specific electronic control unit and the diagnostic device is set separately for each of the plurality of electronic control units excluding the specific electronic control unit; A CAN communication method characterized in that each of the plurality of electronic control units excluding the specific electronic control unit transmits and receives required data for each data ID to and from the diagnostic device via the specific electronic control unit under the CAN ID of the specific electronic control unit, thereby substantially enabling CAN communication between the plurality of electronic control units and the diagnostic device.

2. 2. The CAN communication method according to claim 1, wherein the required data for each data ID is data corresponding to a service ID constituting a request message from the diagnostic device for the electronic control unit corresponding to the data ID.

3. A motor vehicle equipped with a plurality of electronic control units, the plurality of electronic control units include one specific electronic control unit configured to be able to communicate with an externally connected diagnostic device via CAN, and having a CAN ID set for the CAN communication; a data ID configuring a message in CAN communication between the specific electronic control unit and the diagnostic device is set separately for each of the plurality of electronic control units excluding the specific electronic control unit; Each of the plurality of electronic control units excluding the specific electronic control unit transmits and receives required data for each data ID to and from the diagnostic device via the specific electronic control unit under the CAN ID of the specific electronic control unit, thereby making CAN communication between the plurality of electronic control units and the diagnostic device substantially possible.

4. 4. The motor vehicle according to claim 3, wherein the required data for each data ID is data corresponding to a service ID constituting a request message from the diagnostic device for an electronic control unit corresponding to the data ID.

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