Communication device

Abstract

To enhance communication bus redundancy in a PN system to inhibit a communication device from being incapable of being activated when a communication bus is failed.SOLUTION: A communication device 10 comprises: transmission / reception sections 21, 22 connected to communication buses 4, 6; a communication control section 30 for performing data communication with another communication device via the transmission / reception sections; and a power supply control section 24 for supplying power to the communication control section. In a wake-up state, the communication control section makes an activation request signal be transmitted to the other communication device via the communication buses 4, 6. When an activation request signal from the other communication device is received by at least one of the transmission / reception sections 21, 22, the power supply control section supplies power to the communication control section. When no activation request signals are received by all of the transmission / reception sections, the power supply control section stops or inhibits power supply to the communication control section to make the communication control section be into a sleep state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a communication device capable of controlling a sleep / wake-up state via a communication bus. [Background technology]

[0002] A partial network (hereinafter referred to as PN) is known, which selectively activates a specific communication device by sending an NM message with identification information that specifies the communication device to be communicated with on a communication bus to which many communication devices are connected. NM is an abbreviation for Network Management.

[0003] In the PN, if a communication device is unable to receive an NM message, it is unable to communicate. Therefore, Patent Document 1 proposes that an arbitrary activation frame be transmitted on a communication bus in addition to the NM message, and that the communication device be activated when it receives the activation frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2013-255034 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the network system described in Patent Document 1 above, if a fault such as an open or short occurs in the communication bus, neither the NM message nor the startup frame can be sent, making it impossible to start up the desired communication device.

[0006] To solve these problems, it is conceivable to set the power supply that is turned on while the vehicle is running as a startup condition for the communication device in the in-vehicle network system. However, while this measure allows the control by the control device in which the communication device is installed to be performed, it does not achieve the intended purpose of reducing the power consumption of the communication device by the PN.

[0007] An object of one aspect of the present disclosure is to increase the redundancy of a communication bus in a PN system and to prevent a communication device from being unable to start up when the communication bus fails. [Means for solving the problem]

[0008] A communication device according to an aspect of the present disclosure includes a plurality of transceiver units (21, 22) respectively connected to a plurality of communication buses (4, 6), a communication control unit (30), and a power supply control unit (24). The multiple transceivers transmit and receive communication signals to and from other communication devices connected to the multiple communication buses, respectively. The communication control unit performs independent data communication for each of the multiple communication buses with the other communication devices via the multiple transceivers. The power supply control unit supplies power to the communication control unit to bring the communication control unit into a wake-up state in which data communication can be performed.

[0009] Furthermore, when in the wake-up state, the communication control unit periodically transmits a startup request signal from the multiple transceivers via the multiple communication buses to another communication device with which the communication device is to communicate. Furthermore, when at least one of the multiple transceivers receives a startup request signal periodically transmitted from the other communication device to the communication device, the power supply control unit supplies power to the communication control unit to put the communication control unit into the wake-up state. Furthermore, when the startup request signal is no longer received by all of the multiple transceivers, the power supply control unit stops or suppresses the power supply to the communication control unit to put the communication control unit into the sleep state.

[0010] Therefore, according to the communication device of the present disclosure, even if a failure such as an open circuit or a short circuit occurs in some of the multiple communication buses, the communication control unit can be put into a wake-up state by transmitting and receiving a startup request signal to and from other communication devices via the remaining communication buses that are not broken. Also, when startup request signals are no longer received from all of the multiple communication buses, the communication control unit can be put into a sleep state to reduce power consumption in the communication control unit.

[0011] In addition, since the communication control unit performs independent communications via multiple communication buses, the multiple communication buses can be utilized more effectively than if multiple communication buses were used to perform the same data communications in order to increase redundancy in sending and receiving the start-up request signal. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram illustrating a configuration of a network system and a node according to an embodiment. [Diagram 2] 1 is a time chart showing the transmission state of messages on two communication buses. [Diagram 3] 4 is a flowchart showing communication control by a microcomputer. [Figure 4] FIG. 2 is an explanatory diagram showing state transitions of a microcomputer in a node. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. [Embodiment] The network system 2 of this embodiment is, for example, a CAN-based system that is mounted on an automobile and used to control various control targets. CAN is an abbreviation for Controller Area Network. CAN is also a registered trademark.

[0014] As shown in FIG. 1, a network system 2 of this embodiment includes two communication buses 4 and 6, and a plurality of nodes 10, 12, 14, . . . connected to the two communication buses 4 and 6.

[0015] The multiple nodes 10, 12, 14, . . . are communication devices used to control various control objects mounted on an automobile, such as a drive system including an engine and a motor, a braking system including a brake device, and body systems including a door locking mechanism and power windows.

[0016] Although the multiple nodes 10, 12, 14, ... are connected to different external devices, they have the same basic configuration as communication devices. Therefore, the configuration of the multiple nodes 10, 12, 14, ... will be described below by taking the node 10 as an example.

[0017] As shown in FIG. 1, the node 10 includes a first transceiver 21 connected to the first communication bus 4 and a second transceiver 22 connected to the second communication bus 6 of the two communication buses 4 and 6.

[0018] The first transceiver 21 and the second transceiver 22 are for transmitting and receiving communication signals between other nodes 12, 14, ... connected to the first communication bus 4 and the second communication bus 6, respectively, and correspond to the multiple transceiver units of the present disclosure.

[0019] 2, the first transceiver 21 and the second transceiver 22 are capable of independent data communication for each of the communication buses 4 and 6 between the other nodes 12, 14, ... connected to the communication buses 4 and 6. The communication buses 4 and 6 are provided for each type of control object, such as the drive and braking system and body system of an automobile, and the communication buses 4 and 6 are used to transmit data used to control each of these control objects.

[0020] Furthermore, the first transceiver 21 and the second transceiver 22 can select a node to communicate with from among the nodes 12, 14, ... connected to the communication buses 4, 6 by periodically transmitting and receiving NM messages via the communication buses 4, 6. In other words, the first transceiver 21 and the second transceiver 22 are PN-compatible transceivers that can configure a PN (i.e., a partial network) for each of the communication buses 4, 6.

[0021] Next, the node 10 includes a microcomputer 30 having a function as a communication control unit of the present disclosure, and a power supply control unit 24 that controls the power supply of the microcomputer 30. The microcomputer 30 is a well-known microcomputer including a CPU, a ROM, a RAM, etc., and functions as controllers 31, 32, a main control unit 34, an input / output unit 36, and an NM control unit 38 by the CPU executing a program stored in the ROM.

[0022] The controller 31 is for performing data communication with the other nodes 12, 14, . . . via the first transceiver 21 by inputting and outputting transmission and reception data to and from the first transceiver 21.

[0023] Similarly, the controller 32 is for performing data communication with the other nodes 12, 14, . . . via the second transceiver 22 by inputting and outputting transmission and reception data to and from the second transceiver 22.

[0024] The main control unit 34 outputs transmission data to the controllers 31 and 32 and obtains reception data from the controllers 31 and 32, thereby carrying out data communication using the first transceiver 21 and the second transceiver 22.

[0025] In addition, the input / output unit 36 ​​is for outputting received data acquired from other nodes 12, 14, ... to an external device that controls the controlled object, and for taking in signals from external devices such as sensors, operating devices, and control devices as input data.

[0026] In addition to the above data communication, the main control unit 34 also performs input / output processing to input and output various data between the external device and the main control unit 34 via the input / output unit 36. The main control unit 34 also performs transmission processing to transmit various data acquired from the external device in the input / output processing to the other nodes 12, 14, ... through the above data communication.

[0027] On the other hand, the NM control unit 38, in accordance with a command from the main control unit 34, generates NM messages for other nodes 12, 14, ... with which it will communicate, and causes the controllers 31, 32 to simultaneously and periodically output the NM messages to the first transceiver 21 and the second transceiver 22. Therefore, the NM messages are periodically transmitted at times t1, t2, t3, ... on both the first communication bus 4 and the second communication bus 6, as shown in FIG.

[0028] The NM message is a communication frame of a predetermined data length that controls the start / stop of communication of the other nodes 12, 14, ... connected to the communication buses 4, 6. The NM control unit 38 then adds identification information for identifying the other nodes 12, 14, ... as communication partners to the NM message, thereby starting up the microcomputers 30 of the other nodes 12, 14, ... as communication partners, and carrying out the above-mentioned data communication.

[0029] Therefore, when the first transceiver 21 and the second transceiver 22 receive an NM message transmitted from another node 12, 14, ..., they can determine from the identification information contained in the NM message whether the NM message is a startup request signal for their own node 10.

[0030] Then, when the first transceiver 21 and the second transceiver 22 determine that the received NM message is a wake-up request signal for the node 10, they output a wake-up signal (hereinafter, WU signal) to the power supply control unit 24.

[0031] In addition, when the first transceiver 21 and the second transceiver 22 are unable to receive an NM message, which is a startup request signal for their own node 10, for a predetermined period of time longer than the communication period of the NM message after starting to output the UW signal, they stop outputting the WU signal.

[0032] An input signal from an external device to the input / output unit 36 ​​is also input to the first transceiver 21 and the second transceiver 22. Then, the first transceiver 21 and the second transceiver 22 determine from the input signal whether or not a start-up condition caused by the own node 10 is satisfied, and also output a WU signal to the power supply control unit 24 when it is determined that the start-up condition is satisfied.

[0033] Next, when a WU signal is input from at least one of the first transceiver 21 and the second transceiver 22, the power supply control unit 24 supplies power to the microcomputer 30, thereby putting the microcomputer 30 into a wake-up state.

[0034] Furthermore, when the WU signal is not input from both the first transceiver 21 and the second transceiver 22, the power supply control unit 24 stops or reduces the power supply to the microcomputer 30, and puts the microcomputer 30 into a sleep state.

[0035] In this way, the power supply control unit 24 starts supplying power to the microcontroller 30 when the startup conditions of the node 10 are met or when a startup request is received from another node 12, 14, ... in accordance with the WU signals input from the first transceiver 21 and the second transceiver 22.

[0036] In response to this, the microcomputer 30 starts up and enters a wake-up state when it receives power supply from the power supply control unit 24. In the wake-up state, the microcomputer 30 performs a communication control process for performing data communication with the other nodes 12, 14, ... in the procedure shown in FIG.

[0037] Furthermore, when the power supply from the power supply control unit 24 is stopped or suppressed and the microcomputer 30 enters a sleep state, the microcomputer 30 stops normal control operations and is therefore unable to perform the above-mentioned data communication. As a result, power consumption in the microcomputer 30 is suppressed.

[0038] As shown in FIG. 3, in the communication control process performed when the microcomputer 30 is in a wake-up state, first, in S110, it is determined whether or not a start-up condition caused by the own node 10 is satisfied.

[0039] If it is determined in S110 that the start condition is met, the process proceeds to S120, where an NM message transmission setting process is executed to cause the NM control unit 38 to generate an NM message for the other nodes 12, 14, . . . that will be the communication partners.

[0040] As a result, as shown in FIG. 2, the NM message generated by the NM control unit 38 is simultaneously transmitted from the first transceiver 21 and the second transceiver 22 to the first communication bus 4 and the second communication bus 6 repeatedly at a predetermined period.

[0041] In addition, when the NM message is sent in S120 in this manner, the process proceeds to S130, and data is sent to the other nodes 12, 14, ... with which the node 10 is to communicate, thereby performing active data communication initiated by the node 10 itself with the other nodes 12, 14, ....

[0042] On the other hand, if it is determined in S110 that the activation condition is not met, the process proceeds to S140, where the generation of the NM message by the NM control unit 38 is stopped, thereby stopping the transmission of the NM message.

[0043] Then, in the next step S150, passive data communication is performed based on the data transmitted from the communication partner. The communication control process from S110 to S150 is repeatedly performed by the microcomputer 30.

[0044] As described above, the microcomputer 30 is switched to the sleep state or the wake-up state by the power supply control unit 24, and executes the above-mentioned communication control process when in the wake-up state. As a result, the microcomputer 30 is in one of the sleep state, the active communication state, and the passive communication state, as shown in FIG.

[0045] That is, when the microcomputer 30 is in a sleep state and a start-up condition caused by the node 10 is satisfied, the microcomputer 30 goes into an active communication state. In this communication state, the microcomputer 30 causes the NM control unit 38 to generate an NM message common to the first communication bus 4 and the second communication bus 6 and transmit the message from the first and second transceivers 21, 22 to the communication buses 4, 6.

[0046] As a result, the microcomputer 30 can use the identification information added to the NM message to start up the microcomputer of a specific node among the other nodes 12, 14, ... connected to each communication bus 4, 6, and perform active data communication.

[0047] Also, in the active communication state, if the start condition caused by the node 10 itself is no longer satisfied, the microcomputer 30 goes into a passive communication state in which data communication is performed based on data transmitted from the communication partner. In this passive communication state, the microcomputer 30 stops transmitting NM messages and performs passive data communication with the other communication partner nodes 12, 14, ...

[0048] In this state, if an NM message for the node 10 is not received from either the first transceiver 21 or the second transceiver 22 for a predetermined period of time or longer, the power supply from the power supply control unit 24 is stopped or reduced, and the microcontroller 30 enters a sleep state.

[0049] Furthermore, when the microcomputer 30 is in a sleep state and receives an NM message transmitted to the node 10 from the other nodes 12, 14, ... via at least one of the first transceiver 21 and the second transceiver 22, the microcomputer 30 is started up by power supply from the power supply control unit 24. When started up in this way by an NM message transmitted from the other nodes 12, 14, ..., the microcomputer 30 goes into a passive communication state.

[0050] Furthermore, when the microcomputer 30 is in a passive communication state, if a start-up condition caused by the node 10 is satisfied, the microcomputer 30 goes into an active communication state and performs data communication with the other nodes 12, 14, ... that are its communication partners. When the communication state of the microcomputer 30 is changed from passive to active in this way, an NM message is also transmitted to the other nodes 12, 14, ... that are its communication partners.

[0051] As described above, in the network system 2 of this embodiment, when each of the nodes 10, 12, 14, ..., which are communication devices, is in an active communication state, the NM control unit 38 transmits an NM message to the other nodes 10, 12, 14, ..., which are to communicate with it. Then, the other nodes 10, 12, 14, ..., which receive the NM message, enter a passive communication state and perform data communication with the other nodes 10, 12, 14, ..., which transmitted the NM message.

[0052] This data communication is performed independently for each control system, such as the drive / brake system and the body system, using the first communication bus 4 and the second communication bus 6, respectively, but the NM message is generated by one NM control unit 38 that is common to the first and second communication buses 4, 6. The generated NM message is then transmitted to both the first and second communication buses 4, 6.

[0053] Therefore, even if a fault such as an open / short occurs in one of the first and second communication buses 4, 6, the NM message can be transmitted to the communication partner nodes 10, 12, 14, . . . via the non-faulty communication bus.

[0054] Therefore, even if the first communication bus 4 or the second communication bus 6 fails, the microcomputer 30 of the communication partner node 10, 12, 14, ... can be started, and the microcomputer 30 can detect the failure of the first communication bus 4 or the second communication bus 6. Therefore, for example, it is possible to notify an external device connected to the input / output unit 36 ​​of the failure of the communication bus and have the external device control the controlled object using preset fail-safe data.

[0055] Furthermore, the microcomputer 30 performs independent data communication via the first communication bus 4 and the second communication bus 6. Therefore, the first communication bus 4 and the second communication bus 6 can be used more effectively than when multiple communication buses are simply provided and the same data communication is performed via each communication bus in order to increase redundancy in sending and receiving NM messages.

[0056] [Other embodiments] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0057] For example, in the above embodiment, the multiple nodes 10, 12, 14, ..., which are communication devices, are described as being mounted on an automobile and constituting a network system 2 using a CAN, but the communication device of the present disclosure can also be applied to network systems other than CAN. Also, it can be applied to network systems other than automobiles.

[0058] Further, the network system 2 of the above embodiment has been described as being provided with two communication buses 4, 6, and the nodes 10, 12, 14, . . . which are communication devices, are connected to both of the communication buses 4, 6.

[0059] However, even if the communication device of the present disclosure is connected to three or more communication buses, the same effect can be obtained by operating it in the same manner as in the above embodiment. Also, the communication device of the present disclosure can be applied to a network system in which another communication device is connected to only one of multiple communication buses, apart from the other communication buses that transmit and receive NM messages via the multiple communication buses.

[0060] In addition, in the above embodiment, the startup request signal transmitted and received between other communication devices connected to multiple communication buses was described as an NM message, but the startup request signal is not limited to an NM message and may be another communication frame.

[0061] The communication control unit and the method of the present disclosure may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the communication control unit and the method of the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the communication control unit and the method of the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transient tangible recording medium as instructions executed by a computer. The method of realizing the functions of each unit included in the communication control unit does not necessarily need to include software, and all of the functions may be realized using one or more hardware.

[0062] A plurality of functions possessed by one component in the above embodiments may be realized by a plurality of components, or a single function possessed by one component may be realized by a plurality of components. A plurality of functions possessed by a plurality of components may be realized by a single component, or a single function realized by a plurality of components may be realized by a single component. A part of the configuration of the above embodiments may be omitted. At least a part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0063] The technology disclosed herein can be realized in various forms, such as the communication devices constituting the above-mentioned nodes 10, 12, 14, ..., as well as a system including the communication devices as components, a program for causing a computer to function as a communication device, a non-transient physical recording medium such as a semiconductor memory on which the program is recorded, and a communication method. [Technical idea disclosed in this specification] [Item 1] a plurality of transceivers (21, 22) respectively connected to the plurality of communication buses (4, 6) and configured to transmit and receive communication signals to and from other communication devices connected to the plurality of communication buses; a communication control unit (30) configured to perform independent data communication for each of the plurality of communication buses with the other communication device via the plurality of transmission / reception units; a power supply control unit (24) configured to supply power to the communication control unit to bring the communication control unit into a wake-up state in which the data communication can be performed; Equipped with When in the wake-up state, the communication control unit periodically transmits a start-up request signal from the plurality of transmission / reception units to the other communication device to be started as a communication partner via the plurality of communication buses; A communication device, wherein the power supply control unit is configured, when at least one of the multiple transceivers receives the startup request signal periodically transmitted from the other communication device to the communication device, to supply power to the communication control unit to put the communication control unit into the wake-up state, and, when the startup request signal is no longer received by all of the multiple transceivers, to stop or reduce the power supply to the communication control unit to put the communication control unit into the sleep state.

[0064] [Item 2] Item 1 is a communication device according to the present invention, A communication device, wherein the power supply control unit is configured to, when a startup condition of the communication device is satisfied while the communication control unit is in the sleep state, put the communication control unit into the wake-up state and start transmitting the startup request signal from the multiple transceivers.

[0065] [Item 3] The communication device according to item 1 or 2, A communication device, wherein the power control unit is configured to put the communication control unit into the wake-up state when the startup request signal transmitted from the other communication device is received by at least one of the multiple transceivers when the communication control unit is in the sleep state.

[0066] [Item 4] A communication device according to any one of items 1 to 3, The communication control unit is configured to transmit a communication frame including identification information that identifies a communication device that should be activated as a communication partner among the other communication devices connected to the multiple communication buses as the activation request signal from the multiple transceivers to the multiple communication buses.

[0067] [Item 5] A communication device according to any one of items 1 to 4, the communication control unit includes an NM control unit (38) common to the plurality of transmission / reception units, The NM control unit is configured to generate an NM message that controls the start / stop of communication of the other communication device to be activated as a communication partner, and to output the generated NM message to the multiple transceiver units as the activation request signal. [Explanation of symbols]

[0068] 4...first communication bus, 6...second communication bus, 10, 12, 14...nodes, 21...first transceiver, 22...second transceiver, 24...power supply control unit, 30...microcomputer.

Claims

1. a plurality of transceivers (21, 22) respectively connected to the plurality of communication buses (4, 6) and configured to transmit and receive communication signals to and from other communication devices connected to the plurality of communication buses; a communication control unit (30) configured to perform independent data communication for each of the plurality of communication buses with the other communication device via the plurality of transmission / reception units; a power supply control unit (24) configured to supply power to the communication control unit to bring the communication control unit into a wake-up state in which the data communication can be performed; Equipped with When in the wake-up state, the communication control unit periodically transmits a start-up request signal from the plurality of transmission / reception units to the other communication device to be started as a communication partner via the plurality of communication buses; A communication device, wherein the power supply control unit is configured to supply power to the communication control unit to put the communication control unit into the wake-up state when the startup request signal periodically transmitted from the other communication device to the communication device is received by at least one of the multiple transceivers, and to stop or reduce the power supply to the communication control unit to put the communication control unit into the sleep state when the startup request signal is no longer received by all of the multiple transceivers.

2. 2. The communication device according to claim 1, A communication device, wherein the power supply control unit is configured to, when a startup condition of the communication device is satisfied while the communication control unit is in the sleep state, put the communication control unit into the wake-up state and start transmitting the startup request signal from the multiple transceivers.

3. The communication device according to claim 1 or 2, A communication device, wherein the power supply control unit is configured to put the communication control unit into the wake-up state when the startup request signal transmitted from the other communication device is received by at least one of the multiple transceivers when the communication control unit is in the sleep state.

4. 2. The communication device according to claim 1, The communication control unit is configured to transmit a communication frame including identification information that identifies a communication device that should be activated as a communication partner among the other communication devices connected to the multiple communication buses as the activation request signal from the multiple transceivers to the multiple communication buses.

5. 2. The communication device according to claim 1, The communication control unit includes an NM control unit (38) common to the plurality of transmission / reception units, The NM control unit of the communication device is configured to generate an NM message that controls the start / stop of communication of the other communication device to be activated as a communication partner, and to output the generated NM message to the multiple transceiver units as the activation request signal.

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