In-vehicle network system and control method for an in-vehicle network system

Abstract

The system is configured to switch the power supply to the lower-level ECU from a stopped state to a supplied state in response to a startup command message, while also allowing for precise control over the supply and shutdown of power to the lower-level ECU. [Solution] The power / startup management ECU 10 receives NM messages that selectively instruct the startup of multiple lower-level ECUs 26 and 30, transmitted via the communication bus 24, on behalf of the multiple lower-level ECUs 26 and 30. The power / startup management ECU 10 then turns on the relay circuits 18 and 20 connected to the lower-level ECUs 26 and 30 that have been instructed to start by the NM messages. This allows the lower-level ECUs 26 and 30 that have been instructed to start to be put into an activated state.

Description

Technical Field

[0001] The present disclosure relates to an in-vehicle network system having a plurality of control devices connected to a communication bus and capable of communicating with each other in a vehicle, and a control method for the in-vehicle network system.

Background Art

[0002] For example, Patent Document 1 discloses an in-vehicle network system including a host ECU, an intermediate ECU, and a subordinate ECU. In the in-vehicle network system of Patent Document 1, the intermediate ECU is supplied with power from a power source, and supplies power from the power source to the subordinate ECU according to a message received from the host ECU. That is, the intermediate ECU maintains the subordinate ECU in a power-off state until a message is received from the host ECU. When a message from the host ECU is received by the intermediate ECU, the subordinate ECU is supplied with power from the power source. The subordinate ECU transitions from the power-off state to a standby state of waiting for an instruction by this power supply.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the in-vehicle network system described in Patent Document 1, the subordinate ECU is powered off until the intermediate ECU receives a message from the host ECU. Therefore, compared with simply putting the subordinate ECU in a standby state (sleep state), the power consumption of the subordinate ECU can be reduced.

[0005] However, in the in-vehicle network system described in Patent Document 1, the intermediate ECU is configured to supply power from the power source to all lower-level ECUs when it receives a message from the higher-level ECU. In other words, the multiple lower-level ECUs connected to the intermediate ECU are always simultaneously supplied with or shut off power.

[0006] Thus, if the relationship between the intermediate ECU that manages the supply and shutdown of power and the subordinate ECU that it manages is fixed, it becomes difficult to finely control the supply and shutdown of power to the subordinate ECU. For example, when setting up a cluster, which is a group of ECUs that start up simultaneously in order to realize a desired function, it is possible that at least one ECU may belong to multiple clusters. However, in the in-vehicle network system of Patent Document 1, it is not possible to manage the power of one subordinate ECU with two or more intermediate ECUs, so it is difficult to meet such requirements.

[0007] This disclosure has been made in view of the above-mentioned points, and aims to provide an in-vehicle network system and a control method for an in-vehicle network system that can finely manage the supply and shutdown of power to a lower-level control device, while being configured to switch the power supply of the lower-level control device from a stopped state to a supplied state in response to a message requesting activation. [Means for solving the problem]

[0008] To achieve the above objective, the in-vehicle network system according to this disclosure is an in-vehicle network system (100) having a plurality of control devices (10, 26, 30, 34, 40) connected to a communication bus (24) in a vehicle and capable of communicating with each other, Multiple control devices include at least one higher-level control device (10) and multiple lower-level control devices (26, 30), The higher-level control unit is A power management unit (14) that turns on and off multiple relay circuits (18, 20) provided on each power supply line (6) of multiple lower-level control devices, The system includes a startup management unit (12) that receives network management messages (hereinafter referred to as NM messages) transmitted via a communication bus, which selectively instruct the startup of multiple lower-level control devices, on behalf of the multiple lower-level control devices, and instructs the power management unit to turn on the relay circuits provided on the power supply lines of the lower-level control devices that have been instructed to start by the NM messages, thereby putting the lower-level control devices that have been instructed to start into a startup state.

[0009] Furthermore, the control method for an in-vehicle network system according to this disclosure is a control method for an in-vehicle network system (100) having a plurality of control devices (10, 26, 30, 34, 40) connected to a communication bus (24) and capable of communicating with each other in a vehicle, Multiple control devices include at least one higher-level control device (10) and multiple lower-level control devices (26, 30), The higher-level control unit has a power management unit (14) that turns on and off multiple relay circuits (18, 20) provided on each power supply line (6) of multiple lower-level control units. The higher-level control unit receives network management messages (hereinafter referred to as NM messages) transmitted via the communication bus on behalf of the multiple lower-level control units, which selectively instruct the activation of the multiple lower-level control units (S100), and The higher-level control unit activates a relay circuit located on the power supply line of the lower-level control unit that has been instructed to be activated by an NM message, thereby putting the lower-level control unit into an activated state (S130).

[0010] According to the in-vehicle network system and control method for the in-vehicle network system disclosed herein, a higher-level control unit (10) receives NM messages on behalf of the multiple lower-level control units (26, 30) that selectively instruct the activation of the multiple lower-level control units transmitted via a communication bus (24). The higher-level control unit then activates the lower-level control units that have been instructed to be activated by the NM messages by turning on relay circuits (18, 20) provided on the power supply lines (6) of the lower-level control units that have been instructed to be activated.

[0011] Accordingly, the in-vehicle network system and control method for the in-vehicle network system according to this disclosure enable the power supply to the lower-level control unit to be switched from a stopped state to a supplied state in response to an NM message instructing startup, while also enabling fine-grained control of the power supply and shutdown to the lower-level control unit.

[0012] The reference numbers in parentheses above are merely examples of correspondences with specific configurations in embodiments described later, in order to facilitate understanding of this disclosure, and are not intended to limit the scope of this disclosure in any way.

[0013] Furthermore, technical features described in each claim of the patent claims, other than those described above, will become clear from the description of the embodiments and the accompanying drawings, which will be discussed later. [Brief explanation of the drawing]

[0014] [Figure 1] This is a configuration diagram showing an example of the configuration of an in-vehicle network system according to the first embodiment. [Figure 2] This is an explanatory diagram illustrating an example of an NM message, PN request information, and PNC configuration information. [Figure 3] This figure shows an example of a PNC setting table stored in the memory unit of the power / startup management ECU. [Figure 4] This figure shows an example of relay connection information stored in the memory unit of the power / startup management ECU. [Figure 5] This flowchart shows the process performed in the power / startup management ECU in order to make the first and second lower ECUs subject to partial networking in response to NM messages in the first embodiment. [Figure 6] Figure 5 is a flowchart detailing the startup ECU identification process. [Figure 7]A flowchart showing the processing executed in the power / start management ECU in order to target the first and second lower ECUs in the second embodiment for partial networking according to NM messages. [Figure 8] A sequence diagram showing the processing sequence according to the processing shown in the flowchart of FIG. 7. [Figure 9] A configuration diagram showing an example of the configuration of an in-vehicle network system according to the third embodiment.

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of an in-vehicle network system and a control method for an in-vehicle network system according to the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments, and various modifications described hereinafter are also included in the technical scope of the present disclosure. Furthermore, various changes can be made and implemented without departing from the gist of the present disclosure. The embodiments and various modifications can be appropriately combined and implemented as long as there is no technical contradiction. In the following description, the same or similar configurations may be given the same reference numerals in a plurality of drawings, and the description may be omitted. Also, when only a part of the configuration is mentioned, the description described elsewhere can be applied to other parts.

[0016] (First Embodiment) FIG. 1 is a configuration diagram showing an example of the configuration of an in-vehicle network system 100 according to the present embodiment. As shown in FIG. 1, the in-vehicle network system 100 includes a power / start management ECU 10 as an upper control device, first and second lower ECUs 26 and 30 as lower control devices, and first and second normal ECUs 34 and 40. ECU is an abbreviation for Electronic Control Unit (electronic control device).

[0017] Furthermore, the number of first and second subordinate ECUs 26 and 30 connected to the power supply / startup management ECU 10 via the first and second relay circuits 18 and 20, respectively, may be three or more, not just two. Also, the number of first and second subordinate ECUs 26 and 30 connected to each of the first and second relay circuits 18 and 20 may be two or more, not just one. Moreover, within the vehicle, there may be more than one set of combinations of the power supply / startup management ECU 10 and the first and second subordinate ECUs 26 and 30. When multiple sets of combinations of the power supply / startup management ECU 10 and the first and second subordinate ECUs 26 and 30 are provided within the vehicle, each power supply / startup management ECU 10 and the first and second subordinate ECUs 26 and 30 may be connected to each other via the communication bus 24 so that they can communicate with one another.

[0018] The power / startup management ECU 10, the first and second subordinate ECUs 26 and 30, and the first and second normal ECUs 34 and 40 may each be composed of a computer equipped with a processor, memory, and storage, etc. The power / startup management ECU 10, the first and second subordinate ECUs 26 and 30, and the first and normal ECUs 34 and 40 also have communication interfaces (communication IFs) 22, 28, 32, 36, and 42 for communicating with other ECUs.

[0019] A processor is, for example, a CPU, MPU, GPU, or DFP that executes predetermined processes according to a program. Memory is a volatile storage medium, such as RAM, that temporarily stores the results of the processor's calculations. Storage is a non-volatile storage medium, such as flash memory or ROM. Various programs and data executed by the processor are stored in the storage. Some or all of the functions of the power / start management ECU 10, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40 may be implemented by hardware, such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array), rather than by software such as a program.

[0020] The power / startup management ECU 10 may function as a domain controller that oversees the control of the first and second lower-level ECUs 26 and 30, for example. A domain refers to a functional unit when the functions of a vehicle are broadly divided, such as a powertrain domain, chassis domain, advanced driver assistance domain, body domain, or cockpit domain. The above is just one example of domain division, and the domain division may differ from the example above. In addition, the power / startup management ECU 10 may function as an area controller that oversees the control of the lower-level ECUs 26 and 30 located in each area of ​​the vehicle.

[0021] The in-vehicle network system 100 can use CAN (registered trademark, hereinafter the same) as a communication protocol for each ECU 10, 26, 30, 34, and 40 to communicate with each other. However, the communication protocol is not limited to CAN, and the in-vehicle network system 100 may adopt another communication protocol such as CAN-FD. However, in the in-vehicle network system 100 of this embodiment, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40 are divided into multiple groups (these groups are referred to as clusters) for each ECU that needs to be started simultaneously to realize at least one desired function. Then, using network management messages (hereinafter referred to as NM messages) described later, each cluster is switched between a normal operation mode (startup state) and a power saving mode (e.g., sleep state). Note that the power saving mode includes the power-off state of the first and second lower ECUs 26 and 30. For this reason, the communication protocol adopted in the in-vehicle network system 100 must be compatible with sending and receiving NM messages.

[0022] The first and second lower ECUs 26, 30, and the first and second normal ECUs 34, 40 are, for example, control ECUs for controlling a predetermined control object in a vehicle, or sensor ECUs for calculating a predetermined physical quantity based on detection signals detected by sensors. When it is necessary to control a control object or to calculate a predetermined physical quantity based on detection signals from sensors, the first and second lower ECUs 26, 30, and the first and second normal ECUs 34, 40 are activated in normal operation mode and perform normal operations. On the other hand, when it is not necessary to control a control object or to calculate a predetermined physical quantity, the first and second lower ECUs 26, 30, and the first and second normal ECUs 34, 40 are in power-saving mode, in a power-off state or sleep state.

[0023] To switch between this startup state and a power-off or sleep state, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40 are each assigned to a cluster within a group of divided clusters. The assigned cluster is then stored in each ECU as cluster setting information (also referred to as PNC setting information). However, the PNC setting information of the first and second lower ECUs 26 and 30 is stored in the storage unit 16 of the power / startup management ECU 10, as will be described later. Then, in response to a request to start the cluster to which each ECU belongs, based on the startup cluster information (also referred to as PN request information) contained in the NM message, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40 are configured to switch from a power-off or sleep state to a startup state.

[0024] The first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40, each enter a startup state and transition to normal operation mode. While performing their normal operations, they periodically send NM messages to other ECUs. After performing necessary processing, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40, each stop sending periodic NM messages when they no longer need to perform normal operations. When the first and second normal ECUs 34 and 40 have not received NM messages from other ECUs belonging to the same cluster for a predetermined waiting period, they transition from normal operation mode to power-saving mode and switch from the startup state to a sleep state. The first and second lower ECUs 26 and 30 are monitored by the power / startup management ECU 10 for NM messages directed to them. Then, when the time during which no NM messages are received directed to the first and second lower ECUs 26 and 30 reaches a predetermined waiting period, the power / startup management ECU 10 turns off the first and second relay circuits 18 and 20 and stops supplying power to the first and second lower ECUs 26 and 30.

[0025] The first and second normal ECUs 34 and 40 have communication IFs 36 and 42 that can receive NM messages while in sleep mode and switch the first and second normal ECUs 34 and 40 from sleep mode to wake mode in response to the reception of an NM message. When woken up by the communication IFs 36 and 42, the first and second normal ECUs 34 and 40 each determine whether or not their own wake-up is requested based on the PN request information and PNC setting information of the NM message. If they determine that their own wake-up is requested, the first and second normal ECUs 34 and 40 continue in the wake-up state. On the other hand, if they determine that their own wake-up is not requested, the first and second normal ECUs 34 and 40 return to sleep mode. Note that the determination based on the PN request information and PNC setting information of the NM message may be configured to be performed by the communication IFs 36 and 42. In this case, if the communication IF determines that wake-up is requested based on the PN request information and PNC setting information, it transitions the corresponding ECU from sleep mode to wake-up mode. The following provides a detailed explanation of examples of NM messages, PN request information, and PNC configuration information.

[0026] An NM message contains data from bytes 0 to 7, as shown in Figure 2, for example. Byte 0 contains the Node ID (NID). The Node ID is a unique identifier for each of the power / startup management ECU 10, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40. The Node ID allows identification of the source of the NM message. Byte 1 contains the Control Bit Vector (CBV). The Control Bit Vector is data indicating whether or not partial networking is being used. If the Control Bit Vector indicates the use of partial networking, the user data area in bytes 2 to 7 contains PN request information, which is startup cluster information indicating the cluster to be started. Partial networking means that only the ECUs belonging to some clusters are started, while the ECUs belonging to the remaining clusters are powered off or in sleep mode. In this way, by starting only the ECUs that need to operate, the power consumption of each ECU installed in the vehicle can be reduced.

[0027] In the example shown in Figure 2, the control bit vector indicates the use of partial networking, and PN request information is stored in bytes 6 and 7 of the user data area. The user data area from bytes 2 to 5 can be used to transmit any information, such as the ECU activation factor or information regarding normal or abnormal operation. Note that Figure 2 is merely one example of the format of an NM message, and NM messages may take other formats as long as they include information on whether or not partial networking is being used and the PN request information.

[0028] PN request information indicates which clusters should be started and which do not need to be started for each of the multiple divided clusters. More specifically, in the example shown in Figure 2, the clusters are pre-divided into 16. The PN request information contains 16 bits of data corresponding to the 16 divided clusters. In other words, the 16 bits of data in the PN request information are pre-associated with the 16 divided clusters. When each of the 16 bits of data in the PN request information is "0", it indicates that the associated cluster does not need to be started. On the other hand, when each of the 16 bits of data in the PN request information is "1", it indicates that the associated cluster needs to be started.

[0029] As described above, the first and second subordinate ECUs 26 and 30, and the first and second normal ECUs 34 and 40, each possess PNC setting information that indicates the cluster to which they belong among multiple divided clusters. An example of this PNC setting information is shown in Figure 2. Figure 2 shows an example of PNC setting information held by any one of the first and second subordinate ECUs 26 and 30, and the first and second normal ECUs 34 and 40. In the PNC setting information shown in Figure 2, if the associated clusters are classified as A to P from left to right in the figure, the PNC setting information in Figure 2 indicates that the ECU possessing this PNC setting information belongs to clusters D, H, and J. Since the first and second subordinate ECUs 26 and 30, and the first and second normal ECUs 34 and 40 can perform various functions through program execution, they can belong to one or more clusters.

[0030] When the first and second normal ECUs 34 and 40 receive an NM message containing PN request information via their respective communication IFs 36 and 42, they compare the PN request information and PNC setting information bit by bit, as shown in Figure 2, and calculate, for example, a logical AND. In other words, when the first and second normal ECUs 34 and 40 receive an NM message via their respective communication IFs 36 and 42, they enter an activated state. Then, the first and second normal ECUs 34 and 40 determine whether the clusters requested to be activated by the PN request information contained in the NM message match the clusters of the PNC setting information assigned to the first and second normal ECUs 34 and 40, respectively. For example, in the example shown in Figure 2, the clusters requested to be activated by the PN request information are clusters D, G, I, M, N, and O. The clusters to which the ECUs belong, as indicated by the PNC setting information, are clusters D, H, and J. In this case, in cluster D, the clusters requested to be activated by the PN request information contained in the NM message match the clusters of the PNC setting information. Therefore, as shown in Figure 2, the result of the logical AND is "1" in cluster D.

[0031] If the logical AND result results in any bit being "1", the ECU with the PNC configuration information shown in Figure 2 determines that it is being requested to start up. Based on this determination, the ECU with the PNC configuration information shown in Figure 2 transitions from sleep state to startup state, and if it is already in startup state, it maintains that state. On the other hand, if the logical AND result does not result in any bit being "1", and all bits are "0", the ECU with the PNC configuration information shown in Figure 2 determines that it is not being requested to start up. In this case, the ECU with the PNC configuration information shown in Figure 2 discards the received NM message and returns to sleep state.

[0032] Thus, the first and second normal ECUs 34 and 40 have a function to identify whether an NM message requests the startup of their own ECU, based on the PNC setting information. Due to this function to identify NM messages, only the first and second normal ECUs 34 and 40 that have PNC setting information including the cluster that has been requested to start by the PN request information will enter the startup state in response to the NM message. Hereinafter, a communication interface that has the function of receiving an NM message while the ECU is in sleep state and switching the ECU from sleep state to startup state will be referred to as an NM-compatible communication interface.

[0033] In the in-vehicle network system 100 according to this embodiment, the first and second lower ECUs 26 and 30 do not have NM-compatible communication interfaces. In other words, the communication interfaces 28 and 32 of the first and second lower ECUs 26 and 30 are both non-NM-compatible communication interfaces. As described above, an NM-compatible communication interface has the function of receiving an NM message while the ECU is in sleep mode and switching the ECU from sleep mode to wake-up mode. For this reason, an NM-compatible communication interface is more expensive than a non-NM-compatible communication interface. As described above, the communication interfaces 28 and 32 of the first and second lower ECUs 26 and 30 are non-NM-compatible communication interfaces. Therefore, by using a combination of the power / start-up management ECU 10 and the lower ECUs 26 and 30, the overall cost of the in-vehicle network system 100 can be reduced.

[0034] The in-vehicle network system 100 according to this embodiment is characterized in that, despite the fact that the communication IFs 28 and 32 of the first and second lower-level ECUs 26 and 30 are both NM-incompatible communication IFs, the power / startup management ECU 10 is configured such that the first and second lower-level ECUs 26 and 30 are subject to partial networking in response to NM messages. The features of the in-vehicle network system 100 according to this embodiment will be described in detail below.

[0035] As shown in Figure 1, the power / startup management ECU 10 includes a startup management unit 12, a power management unit 14, a storage unit 16, first and second relay circuits 18 and 20, and a communication IF 22. The startup management unit 12 and the power management unit 14 are functional units built within the power / startup management ECU 10 by software and / or hardware. The storage unit 16 may be composed of the storage of the power / startup management ECU 10.

[0036] The first and second relay circuits 18 and 20 of the power / start management ECU 10 are located on the power supply line 6, respectively, for supplying power to the first and second lower ECUs 26 and 30. The power supply circuit 4 can, if necessary, convert the power supply voltage of the vehicle's battery 2 into the operating voltage for the power / start management ECU 10, the first and second lower ECUs 26 and 30, and the first and second normal ECUs 34 and 40. Voltage from the power supply circuit 4 is supplied to the power supply line 6.

[0037] In the example shown in Figure 1, the power lines of the first lower-level ECU 26 are connected to the first power port 18a, which is connected to the first relay circuit 18. Also, the power lines of the second lower-level ECU 30 are connected to the second power port 20a, which is connected to the second relay circuit 20.

[0038] The first and second relay circuits 18 and 20 can be composed of semiconductor switches such as MOSFETs and IGBTs. However, the first and second relay circuits 18 and 20 may be composed of ordinary mechanical relays instead of semiconductor switches. Furthermore, the first and second relay circuits 18 and 20 may be provided inside the power supply / startup management ECU 10, as shown in Figure 1, or they may be provided outside the power supply / startup management ECU 10.

[0039] The communication interface 22 of the power / startup management ECU 10 is an NM-compatible communication interface capable of receiving NM messages. As described above, the communication interfaces 28 and 32 of the multiple lower-level ECUs 26 and 30 are not NM-compatible communication interfaces. In this embodiment, when operation is not required, the multiple lower-level ECUs 26 and 30 enter a power-off state in power-saving mode. Therefore, the communication interfaces 28 and 32 of the multiple lower-level ECUs 26 and 30 cannot receive NM messages when the corresponding lower-level ECUs 26 and 30 are in power-saving mode. For this reason, the communication interface 22 of the power / startup management ECU 10 receives NM messages that selectively instruct the startup of the multiple lower-level ECUs 26 and 30, on behalf of the communication interfaces 28 and 32 of the multiple lower-level ECUs 26 and 30. The NM messages received by the communication interface 22 are provided to the startup management unit 12.

[0040] Here, the storage unit 16 of the power supply / startup management ECU 10 stores, in addition to programs executed by the processor of the power supply / startup management ECU 10, PNC setting information that is assigned to each of the first and second lower ECUs 26 and 30 and indicates the cluster to which each of the first and second lower ECUs 26 and 30 belongs, and relay connection information that indicates the correspondence between the first and second relay circuits 18 and 20 and the first and second lower ECUs 26 and 30. For example, the storage unit 16 can store PNC setting information that indicates the cluster assigned to each of the first and second lower ECUs 26 and 30 using a PNC setting table as shown in Figure 3. The PNC setting table illustrated in Figure 3 shows the correspondence between node IDs, which are unique identifiers of multiple lower ECUs including the first and second lower ECUs 26 and 30, and PNC setting information assigned to multiple lower ECUs including the first and second lower ECUs 26 and 30. Furthermore, the storage unit 16 stores relay connection information that shows the correspondence between the first and second relay circuits 18, 20 and the first and second lower ECUs 26, 30. As illustrated in Figure 4, this information includes the correspondence between the numbers of multiple relay circuits, including the first and second relay circuits 18, 20, or the power port numbers, and the node IDs that indicate the unique identifiers of the multiple lower ECUs, including the first and second lower ECUs 26, 30.

[0041] The startup management unit 12 of the power / startup management ECU 10 can obtain the PNC setting information for each of the first and second lower ECUs 26 and 30 by referring to the PNC setting table illustrated in Figure 3. The startup management unit 12 can then determine which lower ECU 26 or 30 was instructed to start by the NM message, based on the obtained PNC setting information for each lower ECU 26 or 30 and the PN request information of the NM message. Specifically, the startup management unit 12 compares the PN request information of the NM message with the PNC setting information of each of the multiple lower ECUs 26 or 30 bit by bit. Based on the comparison result, if the startup management unit 12 determines that there is PNC setting information that includes a cluster that was requested to start by the PN request information, it determines that the startup of the lower ECU 26 or 30 corresponding to that PNC setting information has been instructed. In this case, the startup management unit 12 provides the power management unit 14 with a node ID indicating the lower ECU 26 or 30 that was instructed to start by the NM message. On the other hand, if the startup management unit 12 determines that there is no PNC configuration information including the cluster that was requested to be started by the PN request information, it discards the NM message because the received NM message does not instruct the startup of any of the lower ECUs 26 or 30.

[0042] When the power management unit 14 of the power / startup management ECU 10 receives the node IDs of the subordinate ECUs 26 and 30 that have been instructed to start up by the startup management unit 12, it refers to the relay connection information stored in the memory unit 16 that shows the correspondence between each relay circuit 18 and 20 and each subordinate ECU 26 and 30. The power management unit 14 then identifies the relay circuits 18 and 20 corresponding to the node IDs of the subordinate ECUs 26 and 30 that have been instructed to start up, and outputs a drive signal to turn on the identified relay circuits 18 and 20. As a result, power is supplied to the subordinate ECUs 26 and 30 that have been instructed to start up via the corresponding relay circuits 18 and 20, and the corresponding subordinate ECUs 26 and 30 enter the startup state.

[0043] The first and second lower ECUs 26 and 30 control various controllable devices mounted on the vehicle that are controlled only when specific conditions are met or under specific environmental conditions (e.g., door locking mechanisms, power window drive motors, headlight light sources, wiper motors, AV equipment, etc.), or calculate predetermined physical quantities necessary for such control based on sensor detection signals. For example, the door locking mechanism is controlled by the door lock control ECU when a vehicle user is about to get into or out of the vehicle. The power window drive motor is controlled by the power window control ECU when the window up / down switch is operated by the user.

[0044] Thus, the first and second lower ECUs 26 and 30 control controlled devices that operate only when specific conditions are met or under specific environments, or calculate predetermined physical quantities necessary for such control. Therefore, when the power / startup management ECU 10 receives an NM message instructing it to start the first and second lower ECUs 26 and 30, it turns on the first and second relay circuits 18 and 20 corresponding to the first and second lower ECUs 26 and 30 to supply power to them. On the other hand, when the power / startup management ECU 10 does not receive an NM message instructing it to start the first and second lower ECUs 26 and 30, it turns off the first and second relay circuits 18 and 20 corresponding to the first and second lower ECUs 26 and 30 to stop supplying power to them. This makes it possible to cut down on the dark current when the operation of each lower ECU 26 and 30 is not required, and further power saving can be achieved for the entire in-vehicle system.

[0045] An NM message may be generated by a power / startup management ECU 10, for example, as a function of a domain controller or area controller. In this case, the power / startup management ECU 10 determines the function to be performed in the vehicle, and if the execution of the desired function is required, it determines the cluster to which the ECUs that need to be in an activated state simultaneously when the relevant function is performed belong, and generates an NM message containing PN request information designating it as the activation cluster. The generated NM message is transmitted via the communication bus 24 to the first and second normal ECUs 34, 40, or other power / startup management ECUs 10, etc. Furthermore, the generated NM message is also used by the power / startup management ECU 10 to determine whether or not its subordinate ECUs 26, 30 need to be switched to an activated state. However, the function of determining the function to be performed in the vehicle and sending an NM message containing PN request information may be possessed by other ECUs, such as the first and second normal ECUs 34, 40, rather than the power / startup management ECU 10.

[0046] Furthermore, the power / startup management ECU 10 may enter a sleep state if all ECUs belonging to the in-vehicle network system 100 are in a sleep state or power-off state and a predetermined period of time has passed during which no NM messages have been received.

[0047] Furthermore, a PNC setting information modification unit 38 for modifying the PNC setting information assigned to each ECU 10, 34, and 40 may be implemented in any of the ECUs belonging to the in-vehicle network system 100, such as the power / startup management ECU 10 and the first and second normal ECUs 34 and 40. Figure 1 shows an example in which the PNC setting information modification unit 38 is implemented in the first normal ECU 34.

[0048] The first normal ECU 34, on which the PNC setting information change unit 38 is implemented, has an external communication device capable of wirelessly communicating with an external server such as a data center 50. The first normal ECU 34 is configured to download application programs for realizing new functions in the vehicle, or update programs for upgrading programs already implemented in any of the ECUs 10, 26, 30, 34, or 40, from the data center 50 via the external communication device. The downloaded programs are provided to the corresponding ECUs 10, 26, 30, 34, or 40 via the communication bus 24, and the installation of new application programs or rewriting with update programs is performed. Note that the ECU that communicates with the external server via the external communication device and the ECU on which the PNC setting information change unit 38 is implemented may be separate ECUs.

[0049] Here, with respect to ECUs 10, 26, 30, 34, and 40 on which new application programs or updates have been implemented, it is possible that, depending on the functionality of the application program or update, it may be necessary to add or change the startup conditions for the corresponding ECU. Therefore, if it is necessary to add or change the startup conditions for an ECU on which an application program or update has been implemented, the data center 50 will have the first normal ECU 34 download new PNC configuration information corresponding to the addition or change in startup conditions, along with the application program or update.

[0050] When the PNC configuration information change unit 38 obtains new PNC configuration information from the data center 50, it changes (rewrites) the PNC configuration information held in the ECUs 10, 26, 30, 34, and 40 on which the application program or update program is implemented to the new PNC configuration information. As a result, the ECUs 10, 26, 30, 34, and 40 on which the application program or update program is implemented switch from sleep state to wake state according to the cluster indicated by the changed PNC configuration information. The rewriting of the PNC configuration information may be performed in the corresponding ECU after receiving a rewrite instruction from the PNC configuration information change unit 38 along with the new PNC configuration information. Alternatively, the rewriting of the PNC configuration information may be performed by the PNC configuration information change unit 38 by accessing the memory of the corresponding ECU.

[0051] The PNC setting information change unit 38 can be located outside the in-vehicle network system 100, for example, in a data center 50, rather than being an ECU belonging to the in-vehicle network system 100. However, if the PNC setting information change unit 38 is implemented in an ECU belonging to the in-vehicle network system 100, the PNC setting information change unit 38 can terminate communication with the outside once it has obtained data from an external source to change the PNC setting information of the ECU. On the other hand, if the PNC setting information change unit 38 is located on a server outside the in-vehicle network system 100, each ECU that needs to change its PNC setting information will need to communicate with the external server individually via an ECU equipped with an external communication device. This may result in the disadvantage of increased communication volume with the external server.

[0052] Next, referring to the flowcharts in Figures 5 and 6, we will explain the processes performed in the power / startup management ECU 10 to make the first and second lower ECUs 26 and 30 targets for partial networking in response to NM messages.

[0053] In step S100, the power / startup management ECU 10 receives an NM message. In step S110, the power / startup management ECU 10 performs a startup ECU identification process to identify the subordinate ECUs 26 and 30 that were instructed to start by the NM message. Details of this startup ECU identification process are shown in the flowchart of Figure 6. The startup ECU identification process will be described below with reference to the flowchart in Figure 6.

[0054] In step S300, the power / startup management ECU 10 identifies the cluster for which startup is requested based on the PN request information in the NM message. In step S310, the power / startup management ECU 10 reads the PNC setting information of multiple lower ECUs 26 and 30 from the storage unit 16. Then, in step S320, the power / startup management ECU 10 identifies the PNC setting information that includes the cluster that matches the cluster for which startup has been requested (startup request cluster) based on the PN request information.

[0055] In step S330, the power / startup management ECU 10 determines whether, in step S320, at least one PNC setting information among the PNC setting information of multiple subordinate ECUs 26 and 30 was identified as PNC setting information containing a cluster that matches the startup request cluster. If at least one PNC setting information is identified, the power / startup management ECU 10 proceeds to the process in step S340. On the other hand, if no identified PNC setting information exists, the power / startup management ECU 10 proceeds to the process in step S350.

[0056] In step S340, the power / startup management ECU 10 sets the subordinate ECUs 26 and 30 corresponding to the identified PNC setting information as start-up ECUs, and sets the other subordinate ECUs 26 and 30 as non-startup ECUs. Then, in step S350, the power / startup management ECU 10 sets all subordinate ECUs 26 and 30 as non-startup ECUs. After that, the power / startup management ECU 10 returns to the process shown in the flowchart of Figure 5.

[0057] In step S120 of the flowchart in Figure 5, the power / startup management ECU 10 determines whether there are any subordinate ECUs 26 and 30 that have been set as startup ECUs. If there are any subordinate ECUs 26 and 30 that have been set as startup ECUs, the power / startup management ECU 10 proceeds to the process in step S130. On the other hand, if there are no subordinate ECUs 26 and 30 that have been set as startup ECUs, the power / startup management ECU 10 terminates the process shown in the flowchart in Figure 5. In this case, the NM message is discarded.

[0058] In step S130, the power / startup management ECU 10 turns on the relay circuits 18 and 20 connected to the lower-level ECUs 26 and 30, which are set as the startup ECUs, based on the relay connection information stored in the memory unit 16 that shows the correspondence between each relay circuit 18 and 20 and each lower-level ECU 26 and 30. The power / startup management ECU 10 also turns off the relay circuits 18 and 20 connected to the lower-level ECUs 26 and 30, which are set as the non-startup ECUs.

[0059] When relay circuits 18 and 20 are turned on, the lower-level ECUs 26 and 30 receive power, as shown in step S200 of the flowchart in Figure 5. As a result, the lower-level ECUs 26 and 30, with relay circuits 18 and 20 turned on, undergo predetermined startup processes in step S210 and enter a startup state.

[0060] As described above, according to the in-vehicle network system 100 of this embodiment, the power / startup management ECU 10 receives NM messages that selectively instruct the startup of multiple lower-level ECUs 26 and 30, transmitted via the communication bus 24, on behalf of the multiple lower-level ECUs 26 and 30. The power / startup management ECU 10 then turns on the relay circuits 18 and 20 connected to the lower-level ECUs 26 and 30 that have been instructed to start by the NM message. As a result, the lower-level ECUs 26 and 30 that have been instructed to start enter the startup state. Therefore, according to the in-vehicle network system 100 of this embodiment, it is possible to finely manage the supply and shutdown of power to the lower-level ECUs 26 and 30 while configuring the system to switch the power supply of the lower-level ECUs 26 and 30 from a stopped state to a supplied state in response to the NM message instructing startup.

[0061] (Second Embodiment) Next, a second embodiment of the in-vehicle network system 100 and the control method for the in-vehicle network system 100 according to this disclosure will be described. In this embodiment, the in-vehicle network system 100 is configured in the same way as the in-vehicle network system 100 of the first embodiment, so a description of the configuration will be omitted.

[0062] Figure 7 is a flowchart showing the process performed in the power supply / startup management ECU 10 according to this embodiment to make the first and second lower ECUs 26 and 30 targets for partial networking in response to NM messages.

[0063] In step S100, the power / startup management ECU 10 receives the NM message, similar to the flowchart in Figure 5. However, in this embodiment, before executing the startup ECU identification process in step S110, the power / startup management ECU 10 turns on all relay circuits 18 and 20 in step S105. As a result, all lower ECUs 26 and 30 begin receiving power, as shown in steps S220 and S240 of the flowchart in Figure 7. Then, in steps S230 and S250, all lower ECUs 26 and 30 undergo predetermined startup processes and enter the startup state.

[0064] Then, after executing the startup ECU identification process in step S110, the power / startup management ECU 10 turns off the relay circuits 18 and 20 connected to the lower ECUs 26 and 30, which are set as non-startup ECUs, in step S135. As a result, the lower ECUs 26 and 30, whose relay circuits 18 and 20 have been turned off, are cut off from power supply, as shown in step S260 of the flowchart in Figure 7.

[0065] As described above, in this embodiment, when the power / startup management ECU 10 receives an NM message that selectively instructs the startup of the lower ECUs 26 and 30, it executes a process to turn on all relay circuits 18 and 20, as shown in the sequence diagram of Figure 8. This makes it possible to start the lower ECUs 26 and 30 earlier compared to when the lower ECUs 26 and 30 corresponding to the startup ECU are started after the startup ECU identification process is performed. Furthermore, as shown in the sequence diagram of Figure 8, the power / startup management ECU 10 immediately executes a process to turn off the relay circuits 18 and 20 connected to the lower ECUs 26 and 30 corresponding to the non-startup ECUs after the startup ECU identification process. Therefore, the in-vehicle network system 100 according to this embodiment can suppress power consumption by the lower ECUs 26 and 30 corresponding to the non-startup ECUs.

[0066] (Third embodiment) Next, a third embodiment of the in-vehicle network system 100 and the control method for the in-vehicle network system 100 according to this disclosure will be described.

[0067] Figure 9 is a configuration diagram showing the configuration of the in-vehicle network system 100 according to this embodiment. The in-vehicle network system 100 according to this embodiment has the same configuration as the in-vehicle network 100 according to the first embodiment. Therefore, the in-vehicle network system 100 according to this embodiment can achieve the same effects as the in-vehicle network system 100 according to the first embodiment. In addition, the in-vehicle network system 100 according to this embodiment is configured such that a start trigger signal for starting either the first or second lower ECU 26, 30 is input to the power supply / start management ECU 10.

[0068] For example, the first and second lower ECUs 26 and 30 may include lower ECUs 26 and 30 that need to be activated by a detection signal from a sensor, a switch operation signal from a user, or an operation signal from an actuator. However, the first and second lower ECUs 26 and 30 are in a power-off state before being switched to the activated state, and therefore cannot be activated by a activation trigger signal.

[0069] Therefore, in the in-vehicle network system 100 according to this embodiment, a start trigger signal for starting at least one subordinate ECU 26, 30, which is generated when predetermined start conditions are met, is input to the power / start management ECU 10. In response to the input of the start trigger signal, the power / start management ECU 10 turns on relay circuits 18, 20 corresponding to at least one of the multiple subordinate ECUs 26, 30 that should be put into an activated state. This makes it possible to put the subordinate ECUs 26, 30 that should be started into an activated state in response to the generation of the start trigger signal.

[0070] It is preferable for the power / startup management ECU 10 to store in the memory unit 16 the correspondence between the startup trigger signal and the lower-level ECUs 26 and 30 that should be in the startup state. This allows the power / startup management ECU 10 to determine which lower-level ECU 26 or 30 should be started when a startup trigger signal is input, by referring to the correspondence stored in the memory unit 16. If there are multiple types of startup trigger signals input to the power / startup management ECU 10, and the lower-level ECUs 26 and 30 that should be in the startup state differ depending on the type of startup trigger signal, storing the above-mentioned correspondence is particularly useful.

[0071] Furthermore, there is no limit to the number of lower-level ECUs 26 and 30 that are activated when a startup trigger signal is input to the power / startup management ECU 10. For example, if the first lower-level ECU 26 and the second lower-level ECU 30 belong to the same cluster, the other lower-level ECU 26 and 30 will be activated when one of them is activated. In such a case, the storage unit 16 may store not only the lower-level ECUs 26 and 30 that should be activated by the startup trigger signal, but also the lower-level ECUs 26 and 30 that belong to the same cluster, as a correspondence between the startup trigger signal and the lower-level ECUs 26 and 30 that should be activated. This makes it possible to activate all lower-level ECUs 26 and 30 that will be activated by the startup trigger signal almost simultaneously.

[0072] Furthermore, the power / startup management ECU 10 may turn on all relay circuits 18 and 20 in response to the input of a start trigger signal, similar to the case of an NM message. Then, the power / startup management ECU 10 refers to the correspondence stored in the memory unit 16 and identifies the lower ECUs 26 and 30 that should be started in response to the input of a start trigger signal. The power / startup management ECU 10 then keeps the relay circuits 18 and 20 connected to the lower ECUs 26 and 30 identified as start ECUs on, and switches the relay circuits 18 and 20 connected to the lower ECUs 26 and 30 identified as non-start ECUs from on to off. This allows the lower ECUs 26 and 30 to be switched to the started state early in response to the start trigger signal.

[0073] (modified version) The systems and methods described in this disclosure may be implemented by a dedicated computer comprising a processor programmed to perform one or more functions embodied by a computer program. The systems and methods described in this disclosure may be implemented using dedicated hardware logic circuits. The systems and methods described in this disclosure may be implemented by one or more dedicated computers comprising a combination of a processor that executes a computer program and one or more hardware logic circuits. For example, some or all of the functions of the power / startup management ECU 10 may be implemented as hardware. Embodiments of implementing a certain function as hardware include embodiments using one or more ICs, etc. Some or all of the functions of the power / startup management ECU 10 may be implemented using a system-on-a-chip (SoC), an integrated circuit (IC), or a field-programmable gate array (FPGA). The concept of an IC also includes an application-specific integrated circuit (ASIC). Furthermore, the computer program only needs to be stored on a computer-readable non-transitory tangible storage medium as instructions executed by the computer. Suitable storage media for the program include HDDs (Hard-disk drives), SSDs (Solid State Drives), flash memory, etc. The scope of this disclosure also includes the form of a program for causing the computer to function as a power / startup management ECU 10, and a non-transitory physical storage medium such as semiconductor memory on which this program is stored.

[0074] (Disclosure of technical ideas) Finally, this specification discloses several technical concepts described in several sections listed below. Some sections may be written in a polynomial form, selectively referencing several preceding sections. Furthermore, some sections may be written in a multiple polynomial form, referencing several sections, including other sections in a polynomial form. These sections written in polynomial and multiple polynomial forms define several technical concepts. Furthermore, the several technical concepts described in the sections listed below also apply to methods for controlling in-vehicle network systems.

[0075] (Technical thought 1) An in-vehicle network system (100) in a vehicle having a plurality of control devices (10, 26, 30, 34, 40) connected to a communication bus (24) and capable of communicating with each other, The plurality of control devices include at least one higher-level control device (10) and a plurality of lower-level control devices (26, 30), The aforementioned higher-level control device is A power management unit (14) that turns on and off multiple relay circuits (18, 20) provided in each power supply line (6) of the multiple lower control devices, An in-vehicle network system having: a startup management unit (12) that receives network management messages (hereinafter referred to as NM messages) transmitted via the communication bus, which selectively instruct the startup of a plurality of the lower-level control devices, on behalf of the plurality of the lower-level control devices, and instructs the power management unit to turn on the relay circuit provided in the power supply line of the lower-level control device that has been instructed to be started by the NM message, thereby starting up the lower-level control device that has been instructed to be started.

[0076] (Technical thought 2) The aforementioned NM message includes startup cluster information that specifies a startup cluster indicating a group of control devices to be started, The higher-level control device has a storage unit (16) that stores cluster setting information indicating the cluster to which the lower-level control device belongs for each of the multiple lower-level control devices, The in-vehicle network system according to Technical Concept 1, wherein the startup management unit determines that the startup cluster specified in the startup cluster information of the NM message matches the cluster in the cluster configuration information, and that the NM message instructs the startup of the lower-level control device corresponding to the relevant cluster configuration information.

[0077] (Technical Thought 3) The in-vehicle network system according to technical concept 2, further comprising a modification unit (38) capable of modifying the cluster setting information of each of the multiple lower-level control units stored in the higher-level control unit.

[0078] (Technical Thought 4) The modified part is implemented in one of the multiple control devices connected to the communication bus, in the in-vehicle network system according to technical concept 3.

[0079] (Technical Thought 5) The above-level control device has a storage unit (16) that stores the cluster setting information of each of the plurality of lower-level control devices and relay connection information indicating the correspondence between the plurality of lower-level control devices and the plurality of relay circuits, wherein the in-vehicle network system is according to any one of technical ideas 2 to 4.

[0080] (Technical Thought 6) The above-level control unit turns on the relay circuit corresponding to the lower-level control unit where the startup cluster specified in the startup cluster information included in the NM message matches the cluster in the cluster setting information, and turns off the relay circuit corresponding to the lower-level control unit where they do not match, based on the cluster setting information and the relay connection information, in the in-vehicle network system according to technical concept 5.

[0081] (Technical Thought 7) The above-level control unit, upon receiving the NM message, before determining whether the startup cluster specified in the startup cluster information matches the clusters in the cluster setting information of each of the multiple lower-level control units, turns on all of the multiple relay circuits to activate all of the multiple lower-level control units, and then determines whether the startup cluster specified in the startup cluster information matches the clusters in the cluster setting information of each of the multiple lower-level control units, keeps the relay circuits corresponding to the matching lower-level control units turned on, and switches the relay circuits corresponding to the non-matching lower-level control units from on to off, as described in Technical Concept 6.

[0082] (Technical Thought 8) At least one of the plurality of subordinate control devices should be put into an activated state when predetermined activation conditions are met. A start trigger signal, which is generated when the predetermined start conditions are met, is input to the higher-level control device. The in-vehicle network system according to any one of technical ideas 1 to 7, wherein the higher-level control device turns on the relay circuit corresponding to at least one of the plurality of lower-level control devices that are to be put into an activated state in response to the input of the activation trigger signal.

[0083] (Technical Thought 9) The above-level control device has a storage unit (16) that stores the lower-level control device to be put into an activated state based on the activation trigger signal, and turns on the relay circuit corresponding to the stored lower-level control device in response to the input of the activation trigger signal, in the in-vehicle network system according to technical concept 8.

[0084] (Technical Thought 10) The above-level control device, in response to the input of the activation trigger signal, turns on all of the multiple relay circuits to activate all of the multiple lower-level control devices, and then keeps the relay circuits corresponding to the stored lower-level control devices turned on, and switches the relay circuits corresponding to the lower-level control devices that are not stored from on to off, in the in-vehicle network system according to technical concept 9. [Explanation of Symbols]

[0085] 2: Battery, 4: Power supply circuit, 6: Power supply line, 10: Power / startup management ECU, 12: Startup management unit, 14: Power management unit, 16: Memory unit, 18: First relay circuit, 20: Second relay circuit, 22: Communication I / F, 24: Communication bus, 26: First subordinate ECU, 28: Communication IF, 30: Second subordinate ECU, 32: Communication IF, 34: First normal ECU, 36: Communication IF, 38: PNC setting information change unit, 40: Second normal ECU, 42: Communication IF, 50: Data center, 100: In-vehicle network system

Claims

1. An in-vehicle network system (100) in a vehicle having a plurality of control devices (10, 26, 30, 34, 40) connected to a communication bus (24) and capable of communicating with each other, The plurality of control devices include at least one higher-level control device (10) and a plurality of lower-level control devices (26, 30), The aforementioned higher-level control device is A power management unit (14) that turns on and off multiple relay circuits (18, 20) provided in each power supply line (6) of the multiple lower control devices, An in-vehicle network system having: a startup management unit (12) that receives network management messages (hereinafter referred to as NM messages) transmitted via the communication bus, which selectively instruct the startup of a plurality of the lower-level control devices, on behalf of the plurality of the lower-level control devices, and instructs the power management unit to turn on the relay circuit provided in the power supply line of the lower-level control device that has been instructed to be started by the NM message, thereby starting up the lower-level control device that has been instructed to be started.

2. The aforementioned NM message includes startup cluster information that specifies a startup cluster indicating a group of control devices to be started, The higher-level control device has a storage unit (16) that stores cluster setting information indicating the cluster to which the lower-level control device belongs for each of the multiple lower-level control devices, The in-vehicle network system according to claim 1, wherein the startup management unit determines, when the startup cluster specified in the startup cluster information of the NM message matches the cluster in the cluster setting information, that the NM message instructs the startup of the lower-level control device corresponding to the relevant cluster setting information.

3. The in-vehicle network system according to claim 2, further comprising a modification unit (38) capable of modifying the cluster setting information of each of the plurality of lower-level control devices stored in the higher-level control device.

4. The in-vehicle network system according to claim 3, wherein the modified part is implemented in one of the plurality of control devices connected to the communication bus.

5. The in-vehicle network system according to any one of claims 2 to 4, wherein the higher-level control device has a storage unit (16) that stores the cluster setting information of each of the plurality of lower-level control devices and relay connection information indicating the correspondence between the plurality of lower-level control devices and the plurality of relay circuits.

6. The in-vehicle network system according to claim 5, wherein the higher-level control unit turns on the relay circuit corresponding to the lower-level control unit whose startup cluster specified in the startup cluster information included in the NM message matches the cluster in the cluster setting information, and turns off the relay circuit corresponding to the lower-level control unit whose cluster does not match, based on the cluster setting information and the relay connection information.

7. The in-vehicle network system according to claim 6, wherein when the higher-level control device receives the NM message, before determining whether the startup cluster specified in the startup cluster information matches the cluster in the cluster setting information of each of the multiple lower-level control devices, it turns on all of the multiple relay circuits to start all of the multiple lower-level control devices, and then determines whether the startup cluster specified in the startup cluster information matches the cluster in the cluster setting information of each of the multiple lower-level control devices, keeps the relay circuit corresponding to the matching lower-level control device turned on, and switches the relay circuit corresponding to the non-matching lower-level control device from on to off.

8. At least one of the plurality of subordinate control devices should be put into an activated state when predetermined activation conditions are met. A start trigger signal, which is generated when the predetermined start conditions are met, is input to the higher-level control device. The in-vehicle network system according to any one of claims 1 to 4, wherein the higher-level control device turns on the relay circuit corresponding to at least one of the plurality of lower-level control devices that should be put into an activated state in response to the input of the activation trigger signal.

9. The in-vehicle network system according to claim 8, wherein the higher-level control device has a storage unit (16) that stores the lower-level control device to be set to an activated state based on the activation trigger signal, and turns on the relay circuit corresponding to the stored lower-level control device in response to the input of the activation trigger signal.

10. The in-vehicle network system according to claim 9, wherein the higher-level control device, in response to the input of the activation trigger signal, turns on all of the plurality of relay circuits to activate all of the plurality of lower-level control devices, and then keeps the relay circuits corresponding to the stored lower-level control devices turned on, and switches the relay circuits corresponding to the lower-level control devices that are not stored from on to off.

11. A control method for an in-vehicle network system (100) having a plurality of control devices (10, 26, 30, 34, 40) connected to a communication bus (24) and capable of communicating with each other, The plurality of control devices include at least one higher-level control device (10) and a plurality of lower-level control devices (26, 30), The higher-level control device has a power management unit (14) that turns on and off a plurality of relay circuits (18, 20) provided in each of the power supply lines (6) of the plurality of lower-level control devices. The higher-level control unit receives network management messages (hereinafter referred to as NM messages) transmitted via the communication bus, which selectively instruct the activation of the multiple lower-level control units, on behalf of the multiple lower-level control units (S100), and A control method for an in-vehicle network system, comprising: the higher-level control unit turning on the relay circuit provided in the power supply line of the lower-level control unit that has been instructed to be started by the NM message, thereby putting the lower-level control unit that has been instructed to be started into an activated state (S130).

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