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

Abstract

To shorten the time it takes for power to be supplied to the lower-level control device, even when the operating mode of the higher-level control device, which has a function to switch the supply and interruption of power to the lower-level control device using a relay, is set to low-power consumption mode. [Solution] The in-vehicle network system 100 includes an NM control master 14 and a power control master 16. The NM control master transmits a startup NM message to the intermediate ECUs 20 and 30, which are in low-power mode, in response to a startup trigger that should cause them to enter normal operation mode. The startup NM message includes a selective instruction to start the lower control devices 40, 50, and 60. Therefore, until a relay control message is given to the intermediate ECU by the power control master, the intermediate ECU can turn on or off the relay circuits 26, 28, and 30 based on the instructions contained in the startup NM message.

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 has a relay capable of switching the supply and cut-off of power from the power source to the subordinate ECU. The intermediate ECU closes the relay 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 power is supplied, the subordinate ECU transitions from the power-off state to a standby state waiting for an instruction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the system of Patent Document 1 described above, the intermediate ECU is configured to be able to receive a message from the host ECU in the standby state. The intermediate ECU transitions from the standby state to the activation state in response to the reception of a message from the host ECU. Then, after transitioning to the activation state, the intermediate ECU sets the relay to the closed state and starts supplying power to the subordinate ECU.

[0005] In order to further reduce power consumption, it is conceivable that an ECU (intermediate ECU in Patent Document 1) equipped with a function to switch between supplying and cutting off power to lower-level ECUs would be configured to be in a low-power mode such as a sleep state or power-off state, where message reception is impossible, rather than a standby state in which message reception is possible.

[0006] However, if the ECU is in low-power mode, it is necessary to transition the ECU from the low-power mode (where it cannot receive messages) to the normal operating mode (corresponding to the startup state in Patent Document 1) where it can receive messages, prior to receiving a message from the higher-level ECU. Furthermore, in this case, after transitioning to the normal operating mode, the ECU will start the process of turning on the relay in response to receiving a message from the higher-level ECU. As a result, a problem arises in that a relatively long time is required before power supply to the lower-level ECU begins.

[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 shorten the time until power supply to a lower-level control device is started, even when the operating mode of a higher-level control device, which has a function to switch the supply and interruption of power to a lower-level control device using a relay, is in a low-power consumption mode. [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, 20, 30, 40, 50, 60) connected to a communication bus (38, 54, 64) in a vehicle and capable of communicating with each other, Multiple control devices include at least one lower control device (40, 50, 60) and at least one higher control device (20, 30) positioned above the lower control device. The higher-level control unit has a normal operation mode and a low-power consumption mode as operating modes, and also has relay control units (24, 34) that turn on and off relay circuits (26, 28, 36) provided on the power supply line (6) of the lower-level control unit. A power control master (16) provides a relay control message to the higher-level control unit that instructs the relay circuit to be turned on or off depending on the vehicle status, The system includes an NM control master (14) that transmits a network management (NM) message to a higher-level control unit via a communication bus, which selectively instructs the activation of a lower-level control unit. The NM control master, in response to the occurrence of a trigger that should cause the higher-level control unit to enter normal operating mode, sends a start NM message to the higher-level control unit, which is currently in low-power mode, that allows the higher-level control unit to transition to normal operating mode. The startup NM message contains a selective instruction to start the lower-level control unit. Until the power control master sends a relay control message to the higher-level control unit, the higher-level control unit turns the relay circuit on or off based on the selective instruction to start the lower-level control unit contained in the startup NM message.

[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, 20, 30, 40, 50, 60) connected to a communication bus (38, 54, 64) in a vehicle and capable of communicating with each other, Multiple control devices include at least one lower control device (40, 50, 60) and at least one higher control device (20, 30) positioned above the lower control device. The higher-level control unit has a normal operation mode and a low-power consumption mode as operating modes, and also has relay control units (24, 34) that turn on and off relay circuits (26, 28, 36) provided on the power supply line (6) of the lower-level control unit. The power control master (16) provides a relay control message to the higher-level control unit that instructs the relay circuit to be turned on or off according to the vehicle status. The NM control master (14) transmits a network management (NM) message via the communication bus to a higher-level control unit, which selectively instructs the lower-level control unit to start up. The NM control master, in response to the occurrence of a trigger that should cause the higher-level control unit to enter normal operating mode, sends a start NM message to the higher-level control unit, which is currently in low-power mode, that allows the higher-level control unit to transition to normal operating mode. The startup NM message contains a selective instruction to start the lower-level control unit. Until the power control master sends a relay control message to the higher-level control unit, the higher-level control unit turns the relay circuit on or off based on the selective instruction to start the lower-level control unit contained in the startup NM message.

[0010] According to the in-vehicle network system and control method for the in-vehicle network system described herein, the NM control master sends a startup NM message to the upper-level control unit, which is in low-power mode, in response to a startup trigger that should cause the upper-level control unit to enter normal operating mode. This startup NM message allows the operating mode of the upper-level control unit to transition from low-power mode to normal operating mode.

[0011] Furthermore, the startup NM message includes a selective instruction to start the lower-level control unit. Therefore, until the relay control message is sent to the higher-level control unit by the power control master, the higher-level control unit can turn the relay circuit on or off based on the selective instruction to start the lower-level control unit contained in the startup NM message. This allows processing to begin supplying power to the lower-level control unit even before the relay control message is sent to the higher-level control unit, thereby shortening the time until power supply begins.

[0012] The reference numbers within the parentheses above only show an example of the correspondence with the specific configurations in the embodiments described below to facilitate the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0013] Also, regarding the technical features described in each claim of the claims other than the features of the present disclosure described above, they will become clear from the description of the embodiments and the accompanying drawings described below.

Brief Description of the Drawings

[0014] [Figure 1] It is a configuration diagram showing an example of the configuration of an in-vehicle network system according to the first embodiment. [Figure 2] It is an explanatory diagram for explaining an example of an NM message, PN request information, and PNC setting information. [Figure 3] It is a sequence diagram when performing relay control processing according to a relay control message after activating a middle ECU that is in a low power consumption mode by an activation NM message. [Figure 4] In the first embodiment, it is a sequence diagram showing an example of the flow of processing executed by a host ECU, a middle ECU, and a lower ECU in response to an activation trigger. [Figure 5] It is a diagram showing an example of a PNC setting table stored in the storage of the middle ECU. [Figure 6] It is a diagram showing an example of relay connection information stored in the storage of the middle ECU. [Figure 7] In the first embodiment, it is a flowchart showing an example of the processing executed by a host ECU, a middle ECU, and a lower ECU respectively when an activation trigger occurs. [Figure 8] In the second embodiment, it is a sequence diagram showing an example of the flow of processing executed by a host ECU, a middle ECU, and a lower ECU in response to an activation trigger. [Figure 9]In the second embodiment, it is a flowchart showing an example of the processes executed by the upper ECU, the middle ECU, and the lower ECU respectively in accordance with the generation of the activation trigger. [Figure 10] It is a configuration diagram showing an example of the configuration of the in-vehicle network system according to a modification.

Embodiments 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 other than those described below. 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 multiple drawings, and the description may be omitted. Also, when only a part of the configuration is mentioned, the description given elsewhere can be applied to other parts.

[0016] (First Embodiment) FIG. 1 is a configuration diagram showing an example of the configuration of the in-vehicle network system 100 according to the present embodiment. The in-vehicle network system 100 shown in FIG. 1 includes an upper ECU 10 as an upper control device, first and second middle ECUs 20, 30 as upper-side control devices, and first to third lower ECUs 40, 50, 60 as lower control devices. ECU is an abbreviation for Electronic Control Unit (electronic control device).

[0017] The in-vehicle network system 100 operates on power supplied from a battery 2 mounted in the vehicle. More specifically, power from the battery 2 is supplied to the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 of the in-vehicle network system 100 via a power supply circuit 4. The power supply circuit 4 can, if necessary, convert the power supply voltage of the battery 2 mounted in the vehicle to the operating voltage of the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60. The power supply lines 6 of the first to third lower ECUs 40, 50, and 60 are provided with first to third relay circuits 26, 28, and 36, which are switched on and off by the first and second intermediate ECUs 20 and 30.

[0018] The configuration of the in-vehicle network system 100 is not limited to the example shown in Figure 1. For example, the number of higher-level ECUs 10 may be two or more, rather than just one. Also, the higher-level ECU 10 may be omitted if any of the intermediate ECUs 20 or 30 also serve as the higher-level ECU 10. The number of intermediate ECUs 20 or 30 may be one or three or more, rather than just two. Regarding the lower-level ECUs 40, 50, and 60, multiple lower-level ECUs may be connected to a single relay circuit 26, 28, or 36. Furthermore, the lower-level ECUs 40, 50, and 60 may include lower-level ECUs that receive power directly from the power supply circuit 4 without going through the relay circuits 26, 28, or 36.

[0019] The upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 may each be composed of a computer equipped with a processor, memory, and storage. The processor is, for example, a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), or DFP (Data Flow Processor) that executes predetermined processes according to a program. Memory is a volatile storage medium that temporarily stores the results of the processor's calculations, such as RAM (Random Access Memory). Storage is a non-volatile storage medium such as flash memory or ROM (Read Only Memory). Various programs and data executed by the processor are stored in the storage. Some or all of the functions of the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50 and 60 may be implemented by hardware, such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), rather than by software such as a program.

[0020] Furthermore, the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50 and 60 are equipped with communication interfaces (communication IFs) 12, 22, 32, 42, 52 and 62 for communicating with other ECUs via communication buses 38, 44, 54 and 64.

[0021] The communication IF 12 of the upper ECU 10 is connected to the communication IFs 22 and 32 of the first and second intermediate ECUs 20 and 30 via the communication bus 38. The first and second intermediate ECUs 20 and 30 can also communicate with each other via this communication bus 38. However, the communication bus connecting the upper ECU 10 to the first and second intermediate ECUs 20 and 30 and the communication bus connecting the first and second intermediate ECUs 20 and 30 to each other may be provided separately. The communication IF 22 of the first intermediate ECU 20 is further connected to the communication IF 42 of the first lower ECU 40 via the communication bus 44. In addition, the communication IF 22 of the first intermediate ECU 20 is connected to the communication IF 52 of the second lower ECU 50 via the communication bus 54. The communication IF42 of the first lower ECU40 and the communication IF52 of the second lower ECU50 may be connected to the communication IF22 of the first intermediate ECU20 via a common communication bus. The communication IF32 of the second intermediate ECU30 is connected to the communication IF62 of the third lower ECU60. The communication IFs22 and 32 of the first and second intermediate ECUs20 and 30 are configured to act as gateways when the upper ECU10 and the first to third lower ECUs40, 50, and 60, which are connected to different communication buses 38, 44, 54, and 64, communicate with each other.

[0022] The in-vehicle network system 100 can use CAN (registered trademark, hereinafter the same) as a communication protocol for the communication IFs 12, 22, 32, 42, 52, and 62 of the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 to communicate with each other. CAN is an abbreviation for Controller Area Network. However, the communication protocol is not limited to CAN, and the in-vehicle network system 100 can employ a variety of communication protocols such as Ethernet (registered trademark), LIN (Local Interconnect Network), FlexRay (registered trademark), and CAN-FD (CAN with Flexible Data Rate). For example, different communication protocols may be used on different communication buses 38, 44, 54, and 64.

[0023] The higher-level ECU 10 may function as a domain controller that oversees the control of the first and second intermediate ECUs 20 and 30, and the first to third lower-level ECUs 40, 50, and 60. 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, and cockpit domain. The above is just one example of domain division, and the domain division may differ from the example above. Alternatively, the higher-level ECU 10 may function as an area controller that oversees the control of the first and second intermediate ECUs 20 and 30, and the first to third lower-level ECUs 40, 50, and 60 located in each area of ​​the vehicle.

[0024] Furthermore, the higher-level ECU 10 has an NM control master 14 that sends a wake-up network management (NM) message as a wake-up signal to the first and second intermediate ECUs 20 and 30 in response to the input of a predetermined wake-up trigger. The wake-up NM message will be described later. The predetermined wake-up trigger may occur, for example, when the vehicle's door locks are unlocked by the user operating a portable key or door handle, when the vehicle's main switch is turned on, or when a higher-level ECU acting as another domain controller notifies that a predetermined vehicle state is in place. Depending on the factor that triggered the wake-up, the NM control master 14 can send a wake-up NM message that allows the first intermediate ECU 20 and / or the second intermediate ECU 30 to be selectively woken up and put into normal operation mode.

[0025] Furthermore, the higher-level ECU 10 has a power control master 16 that instructs the first and second intermediate ECUs 20 and 30 to turn on relay circuits 26, 28, and 36 corresponding to the lower-level ECUs 40, 50, and 60 that need to operate in normal operating mode, based on the vehicle's state (for example, the state of driving, stopping, parking, etc., or the state of operation of various functions of the vehicle by the user) as determined from information obtained from sensors and other ECUs. Specifically, the power control master 16 sends relay control messages to the first and second intermediate ECUs 20 and 30. The relay control messages include instructions on which relay circuits 26, 28, and 36 to turn on and / or which relay circuits 26, 28, and 36 to keep off. Based on the relay control messages, the first and second intermediate ECUs 20 and 30 turn on or off their respective relay circuits 26, 28, and 36. In other words, the power control master 16 can individually instruct multiple intermediate ECUs 20 and 30 to turn on or off their respective relay circuits 26, 28, and 36 via relay control messages, depending on the vehicle's state.

[0026] The first intermediate ECU 20 has first and second relay circuits 26 and 28, and the second intermediate ECU 30 has a third relay circuit 36. The first intermediate ECU 20 also has a first relay control unit 24 that turns the first and second relay circuits 26 and 28 on or off according to the startup NM message and relay control message. The second intermediate ECU 20 has a second relay control unit 34 that turns the third relay circuit 36 ​​on or off according to the startup NM message and relay control message.

[0027] The first relay circuit 26 is located on the power supply line 6 for supplying power to the first lower ECU 40. In other words, the power line of the first lower ECU 40 is connected to the first power port 26a connected to the first relay circuit 26. The second relay circuit 28 is located on the power supply line 6 for supplying power to the second lower ECU 50. In other words, the power line of the second lower ECU 50 is connected to the second power port 28a connected to the second relay circuit 28. The third relay circuit 36 ​​is located on the power supply line 6 for supplying power to the third lower ECU 60. In other words, the power line of the third lower ECU 40 is connected to the third power port 36a connected to the third relay circuit 36.

[0028] The first to third relay circuits 26, 28, and 36 can be configured using semiconductor switches such as MOSFETs and IGBTs. However, the first to third relay circuits 26, 28, and 36 may also be configured using ordinary mechanical relays instead of semiconductor switches. Furthermore, the first to third relay circuits 26, 28, and 36 may be provided inside the first and second intermediate ECUs 20 and 30, as shown in Figure 1, or they may be provided outside the first and second intermediate ECUs 20 and 30.

[0029] The first to third lower ECUs 40, 50, and 60 are, for example, control ECUs for controlling a predetermined control object in a vehicle, or sensor ECUs that calculate 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 to third lower ECUs 40, 50, and 60 are activated and enter normal operation mode, and perform the necessary processing. On the other hand, when it is not necessary to control a control object or calculate a predetermined physical quantity, the first to third lower ECUs 40, 50, and 60 enter a low-power consumption mode and enter a power-off state.

[0030] To switch between this normal operating mode and low power consumption mode, the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 are each assigned to a cluster within a group of divided clusters. The assigned cluster is then stored in each ECU as cluster configuration information (also called PNC configuration information). PNC stands for Partial Networking Clustering. However, the PNC configuration information for the first to third lower ECUs 40, 50, and 60 is stored in the storage of the corresponding intermediate ECUs 20 and 30, as will be described later. Then, in response to a request to start the cluster to which the first to third lower ECUs 40, 50, and 60 belong, based on the startup cluster information (also called PN request information) contained in the NM message, the intermediate ECUs 20 and 30 turn on the relay circuits 26, 28, and 36 connected to the first to third lower ECUs 40, 50, and 60. As a result, the first to third lower ECUs 40, 50, and 60 are switched from a low-power mode, which is a power-off state, to a normal operating mode, which is a power-supplied state.

[0031] When the first to third lower ECUs 40, 50, and 60 start up and transition to normal operation mode, they periodically send NM messages to the other ECUs while performing their normal operations. After the first to third lower ECUs 40, 50, and 60 have completed the necessary processing and no longer need to perform normal operations, they stop sending periodic NM messages. The first and second intermediate ECUs 20 and 30 monitor the NM messages directed to the first to third lower ECUs 40, 50, and 60. When the time during which they do not receive NM messages directed to the first to third lower ECUs 40, 50, and 60 reaches a predetermined waiting time, the first and second intermediate ECUs 20 and 30 turn off the first to third relay circuits 26, 28, and 36, respectively, and stop supplying power to the first to third lower ECUs 40, 50, and 60.

[0032] In this embodiment, the in-vehicle network system 100 includes a higher-level ECU 10, first and second intermediate ECUs 20 and 30, and first to third lower-level ECUs 40, 50, and 60, which are divided into multiple groups (referred to as clusters) for each ECU that needs to be started simultaneously to realize at least one desired function. The system is configured to allow switching between a normal operating mode (startup state) and a low-power consumption mode (sleep state or power-off state) for each cluster using NM messages. The higher-level ECU 10 and the first and second intermediate ECUs 20 and 30 can enter a low-power consumption mode. In this low-power consumption mode, for example, only the function of receiving predetermined Wakeup signals, such as the startup NM message described later, operates in the first and second intermediate ECUs 20 and 30, while other operations are stopped, or power supply to the circuit parts that perform other operations is stopped. This reduces power consumption in the first and second intermediate ECUs 20 and 30 while waiting for a Wakeup signal.

[0033] The following provides a detailed explanation of examples of NM messages, PN request information, and PNC configuration information.

[0034] 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 upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60. 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.

[0035] 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 used and the PN request information. For example, the positions of NID and CBV may be reversed.

[0036] 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. That is, 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. Note that the PN request information may also indicate only the clusters that should be started. Alternatively, the PN request information may also indicate only the clusters that do not need to be started.

[0037] As described above, the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 each possess PNC setting information that indicates the cluster to which they belong among the multiple divided clusters. An example of this PNC setting information is shown in Figure 2. In other words, Figure 2 shows an example of PNC setting information possessed by any one of the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60. In the PNC setting information shown in Figure 2, if the corresponding 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. The first to third lower ECUs 40, 50, and 60 can perform various functions through program execution and other means, and therefore can belong to one or more clusters.

[0038] The upper ECU 10, and the first and second intermediate ECUs 20 and 30, can receive NM messages containing PN request information via their respective communication IFs 12, 22, and 32. Upon receiving an NM message, the upper ECU 10, and the first and second intermediate ECUs 20 and 30 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 upper ECU 10, and the first and second intermediate ECUs 20 and 30 receive an NM message via their respective communication IFs 12, 22, and 32 in low-power mode, they undergo a predetermined startup process to enter normal operation mode.

[0039] The higher-level ECU 10, as well as the first and second intermediate ECUs 20 and 30, then determine whether the clusters requested to be started by the PN request information contained in the NM message match the clusters in the PNC configuration information assigned to each of them. For example, in the example shown in Figure 2, the clusters requested to be started 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 configuration information, are clusters D, H, and J. In this case, in cluster D, the cluster requested to be started by the PN request information contained in the NM message matches the cluster in the PNC configuration information. Therefore, as shown in Figure 2, the result of the logical AND is "1" in cluster D.

[0040] 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 remains in the normal operation mode from the low power mode, or maintains the normal operation mode if it is already in that mode. 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 the low power mode.

[0041] Thus, the upper-level ECU 10, and the first and second intermediate ECUs 20 and 30, have a function to identify whether an NM message requests the activation of their own ECU, based on the PNC setting information. Through this function to identify NM messages, only the upper-level ECU 10, and the first and second intermediate ECUs 20 and 30, which have PNC setting information including the cluster that has been requested to be activated by the PN request information, enter normal operation mode in response to the NM message.

[0042] In this embodiment, when a startup trigger occurs, an NM message is used as a wakeup signal to transition the first and second intermediate ECUs 20 and 30, which are in low-power mode, to normal operation mode. For example, if the first and second intermediate ECUs 20 and 30 transition from low-power mode to normal operation mode in response to a signal of a predetermined level, the startup NM message is defined to include that predetermined level signal. Also, if the first and second intermediate ECUs 20 and 30 transition from low-power mode to normal operation mode in response to the communication IFs 22 and 32 of the first and second intermediate ECUs 20 and 30 receiving an NM message specifying the intermediate ECU as the destination, the startup NM message is defined to include information that the first and second intermediate ECUs 20 and 30 are the destination. In this embodiment, the NM message that transitions the first and second intermediate ECUs 20 and 30, which are in low-power mode, to normal operation mode when a startup trigger occurs is referred to as the startup NM message. Furthermore, the higher-level ECU 10 may not enter a low-power consumption mode, but may always operate in normal operating mode.

[0043] Here, when the first and second intermediate ECUs 20 and 30, which have the function of switching the supply and cutoff of power to the first to third lower ECUs 40, 50, and 60, are in a low-power consumption mode such as sleep state or power cutoff state, for example as shown in Figure 3, upon receiving a wake-up NM message from the NM control master 14, they must first execute a predetermined wake-up process to transition to normal operation mode. Figure 3 shows an example in which the first and second intermediate ECUs 20 and 30 are woken up by the wake-up NM message and enter normal operation mode, and further, relay control processing causes the first and second intermediate ECUs 20 and 30 to turn on the first to third relay circuits 26, 28, and 36 and start supplying power to the first to third lower ECUs 40, 50, and 60.

[0044] During the execution of a predetermined startup process, the first and second intermediate ECUs 20 and 30 cannot receive relay control messages from the power control master 16, or in other words, they cannot decode the relay control messages to determine which relay circuits 26, 28, and 36 should be turned on. Therefore, as shown in Figure 3, the power control master 16 needs to send relay control messages after the startup process has been completed in all intermediate ECUs 20 and 30 and they have transitioned to normal operation mode, for example, after a predetermined startup margin has elapsed. In this way, the first and second intermediate ECUs 20 and 30, which have transitioned to normal operation mode, can receive relay control messages.

[0045] Upon receiving a relay control message, the first and second intermediate ECUs 20 and 30 decode the relay control message as shown in Figure 3, and based on the decoded message, drive the first and second relay control units 24 and 34 to perform relay control processing to turn the first to third relay circuits 26, 28, and 36 on or off. As a result, power supply to the first to third lower ECUs 40, 50, and 60, whose corresponding relay circuits 26, 28, and 36 are turned on, begins. The first to third lower ECUs 40, 50, and 60, with power supply now supplied, operate in normal operation mode after undergoing a predetermined startup process.

[0046] As shown in the example in Figure 3, when the first and second intermediate ECUs 20 and 30 are in low-power consumption mode, a problem may arise in which a relatively long time is required between the occurrence of the startup trigger and the start of power supply to the first to third lower ECUs 40, 50, and 60.

[0047] Therefore, in the in-vehicle network system 100 according to this embodiment, the NM control master 14 sends a startup NM message to the first and second intermediate ECUs 20 and 30, which are in low-power consumption mode, in response to the occurrence of a startup trigger. This message includes a selective instruction (PN request information) to start the first to third lower ECUs 40, 50, and 60. When the first and second intermediate ECUs 20 and 30 transition to normal operation mode in response to the startup NM message, as shown in Figure 4, the first and second intermediate ECUs 20 and 30 execute relay control to turn on or off the first to third relay circuits 26, 28, and 36 based on the selective instruction to start the first to third lower ECUs 40, 50, and 60 included in the startup NM message. As a result, as shown in Figure 4, the relay control can be started even before the relay control message is sent to the first and second intermediate ECUs 20 and 30 by the power control master 16, and power can be supplied to the first to third lower ECUs 40, 50, and 60. As a result, it becomes possible to shorten the time from when the startup trigger occurs until power is supplied to the first to third lower ECUs 40, 50, and 60.

[0048] Furthermore, as shown in Figure 4, the NM control master 14 may repeatedly send startup NM messages at predetermined intervals until the relay control message is sent to the first and second intermediate ECUs 20 and 30 by the power control master 16. This allows the first and second intermediate ECUs 20 and 30 to be activated by the startup NM message and, upon transitioning to normal operation mode, decode the instructions contained in the subsequent startup NM message and, based on the decoded instructions, turn the first to third relay circuits 26, 28, and 36 on or off. Alternatively, after activating all intermediate ECUs 20 and 30 with the initial startup NM message, startup NM messages may be repeatedly sent to the intermediate ECUs 20 and 30 that should maintain normal operation mode. This allows only the intermediate ECUs that need to operate in normal operation mode to remain in normal operation mode, while the other intermediate ECUs return to low-power mode.

[0049] However, the NM control master 14 does not necessarily have to repeatedly send startup NM messages at predetermined intervals. For example, if the communication IFs 22 and 32 of the first and second intermediate ECUs 20 and 30 have a function to save startup NM messages, the first and second intermediate ECUs 20 and 30 can, after starting up and transitioning to normal operation mode, obtain selective instructions to start the first to third lower ECUs 40, 50, and 60 from the saved startup NM messages.

[0050] The following describes the configurations for the first and second intermediate ECUs 20 to turn on or off the first to third relay circuits 26, 28, and 36 based on a startup NM message that includes a selective instruction to start the first to third lower ECUs 40, 50, and 60.

[0051] The storage of the first and second intermediate ECUs 20 and 30 stores PNC setting information that indicates the cluster to which each of the first to third lower ECUs 40, 50, and 60 belongs, in addition to the programs executed by the processors of the first and second intermediate ECUs 20 and 30. Furthermore, the storage of the first and second intermediate ECUs 20 and 30 stores relay connection information that indicates the correspondence between the first to third relay circuits 26, 28, and 36 and the first to third lower ECUs 40, 50, and 60.

[0052] For example, the storage of the first and second intermediate ECUs 20 and 30 can store PNC configuration information indicating the cluster assigned to each of the first to third lower ECUs 40, 50, and 60, using a PNC configuration table as shown in Figure 5. The PNC configuration table illustrated in Figure 5 shows the correspondence between node IDs, which are unique identifiers for multiple lower ECUs including the first to third lower ECUs 40, 50, and 60, and the PNC configuration information assigned to multiple lower ECUs including the first to third lower ECUs 40, 50, and 60.

[0053] Furthermore, the storage of the first and second intermediate ECUs 20 and 30 stores, as relay connection information, the correspondence between the numbers of multiple relay circuits or power port numbers, including the first to third relay circuits 26, 28, and 36, and node IDs that indicate the unique identifiers of multiple lower ECUs, including the first to third lower ECUs 40, 50, and 60, as illustrated in Figure 6.

[0054] The first and second intermediate ECUs 20 and 30, having transitioned to normal operation mode, can obtain the PNC setting information for each of the first to third lower ECUs 40, 50, and 60 by referring to the PNC setting table illustrated in Figure 5. Then, based on the obtained PNC setting information for the first to third lower ECUs 40, 50, and 60 and the PN request information contained in the startup NM message, the first and second intermediate ECUs 20 and 30 can determine which lower ECU 40, 50, and 60 was instructed to start by the startup NM message.

[0055] Specifically, the first and second intermediate ECUs 20 and 30 compare the PN request information contained in the startup NM message with the PNC setting information of each of the multiple lower ECUs 40, 50, and 60 bit by bit. Based on the comparison result, the first and second intermediate ECUs 20 and 30 determine that if there is PNC setting information that includes a cluster that has been requested to be started by the PN request information, then they determine that the startup of the lower ECUs 40, 50, and 60 corresponding to that PNC setting information has been instructed. In this case, the first and second intermediate ECUs 20 and 30 can determine which relay circuits should be turned on and which should be turned off by referring to the relay connection information exemplified in Figure 6, based on the node ID indicating the lower ECUs 40, 50, and 60 that have been instructed to be started by the startup NM message. On the other hand, if the first and second intermediate ECUs 20 and 30 determine that there is no PNC configuration information including the cluster that was requested to be started by the PN request information, they will keep all relay circuits 26, 28, and 36 off, because the received start NM message does not instruct any of the lower ECUs 40, 50, and 60 to start.

[0056] When the first and second intermediate ECUs 20 and 30 determine which relay circuits should be turned on and which should be turned off, they drive the first and second relay control units 24 and 34 to turn on the relay circuits 26, 28, and 36 corresponding to the relay circuits that should be turned on. By performing this relay control process, the lower ECUs 40, 50, and 60, which have been instructed to start by the startup NM message, are supplied with power via the corresponding first to third relay circuits 26, 28, and 36, and enter normal operation mode.

[0057] As described above, the first to third lower ECUs 40, 50, and 60 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 the vehicle user is about to get in 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.

[0058] Thus, the first to third lower ECUs 40, 50, and 60 control controlled devices that operate only when specific conditions are met or under specific environments, and calculate predetermined physical quantities necessary for such control. Therefore, when the first and second intermediate ECUs 20 and 30 are instructed to start the first to third lower ECUs 40, 50, and 60 by a startup NM message, they turn on the first to third relay circuits 26, 28, and 36 corresponding to the first to third lower ECUs 40, 50, and 60, and supply power to the first to third lower ECUs 40, 50, and 60. This makes it possible to start the necessary processing within a short time after the startup instruction is given. On the other hand, if the first and second intermediate ECUs 20 and 30 are not instructed to start the first to third lower ECUs 40, 50, and 60 by the startup NM message, they turn off the first to third relay circuits 26, 28, and 36, respectively, and stop supplying power to the first to third lower ECUs 40, 50, and 60. This cuts down on the dark current when the operation of each lower ECU 40, 50, and 60 is not required, making it possible to further reduce power consumption for the entire in-vehicle system.

[0059] The startup NM message may be generated, for example, by the NM control master 14 of the higher-level ECU 10 as a function of the domain controller or area controller. However, the function of sending the startup NM message in response to the input of a predetermined startup trigger may be possessed by at least one other ECU, such as other higher-level ECUs, first and second intermediate ECUs 20, 30, and / or first to third lower-level ECUs 40, 50, 60, in addition to or instead of the higher-level ECU 10. In other words, multiple NM control masters 14 may be provided in the in-vehicle network system. For example, if one of the first and second intermediate ECUs 20, 30 is operating in normal operation mode and the other is in low-power mode, the intermediate ECU operating in normal operation mode may send the startup NM message to the intermediate ECU in low-power mode.

[0060] If the first and second intermediate ECUs 20 and 30 receive activation NM messages from multiple ECUs (i.e., NM control masters) at the same time, it is preferable that the first and second intermediate ECUs 20 and 30 turn on the corresponding first to third relay circuits 26, 28, and 36 if any of the activation NM messages instruct the activation of at least one of the first to third lower ECUs 40, 50, and 60. This makes it possible to properly supply power to the first to third lower ECUs 40, 50, and 60 even if multiple NM control masters are provided in the in-vehicle network system 100.

[0061] Furthermore, when the first and second intermediate ECUs 20 and 30 turn on at least one of the first to third relay circuits 26, 28, and 36 based on instructions included in the startup NM message, it is preferable that they turn on the corresponding first to third relay circuits 26, 28, and 36 for a predetermined time. The time for turning on the relay circuits 26, 28, and 36 can be, for example, until the power control master 16 starts transmitting a relay control message after the first and second intermediate ECUs 20 and 30 have transitioned to normal operation mode.

[0062] As described above, the power control master 16 determines the function to be performed in the vehicle based on the vehicle's state, which is determined by various sensor signals and information obtained from other ECUs. If the power control master 16 determines that at least one of the first to third lower ECUs 40, 50, and 60 needs to operate in normal operating mode, it sends a relay control message instructing the corresponding relay circuits 26, 28, and 36 to be turned on. On the other hand, if the power control master 16 determines that the first to third lower ECUs 40, 50, and 60 do not need to operate in normal operating mode, it sends a relay control message instructing the first to third relay circuits 26, 28, and 36 to be turned off.

[0063] Thus, the power control master 16 determines whether to turn on or off the first to third relay circuits 26, 28, and 36 based on the vehicle's state, and gives instructions to the first and second intermediate ECUs 20 and 30 via relay control messages. Therefore, after the power control master 16 gives relay control messages to the first and second intermediate ECUs 20 and 30, it is preferable that the first and second intermediate ECUs 20 and 30 prioritize instructions from relay control messages over instructions from startup NM messages when turning on or off the first to third relay circuits 26, 28, and 36.

[0064] Specifically, the first and second intermediate ECUs 20 and 30 turn on or off the first to third relay circuits 26, 28, and 36 based on instructions from the activation NM message until a relay control message is received. However, once the first and second intermediate ECUs 20 and 30 receive a relay control message, they again turn on or off the first to third relay circuits 26, 28, and 36 based on instructions from the relay control message.

[0065] Here, due to some factor, after the first and second intermediate ECUs 20 and 30 transition to normal operation mode, relay control messages from the power control master 16 may not reach the first and second intermediate ECUs 20 and 30 at the scheduled time. In such cases, if relay control messages cannot be obtained, there is a risk that relay circuits 26, 28, and 36, which do not need to be turned on, will remain turned on. In this regard, as described above, if the first and second intermediate ECUs 20 and 30 turn on the corresponding first to third relay circuits 26, 28, and 36 for a predetermined time based on the instructions included in the startup NM message, it is possible to prevent relay circuits 26, 28, and 36 that do not need to be turned on from remaining turned on.

[0066] Next, with reference to the flowchart in Figure 7, an example of processing performed in the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 in response to the occurrence of a startup trigger will be described. Note that the execution of the processing shown in the flowchart in Figure 7 by the upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 corresponds to the execution of the in-vehicle network system control method in this disclosure.

[0067] In step S100, the higher-level ECU 10 determines whether or not a startup trigger has occurred. If it determines that a startup trigger has occurred, the higher-level ECU 10 proceeds to the process in step S110. If it determines that a startup trigger has not occurred, the higher-level ECU 10 repeats the process in step S100.

[0068] In step S110, a Wakeup instruction, i.e., a startup NM message, is sent to the first and second intermediate ECUs 20 and 30. This startup NM message contains selective startup instructions (PN request information) for the first to third lower ECUs 40, 50, and 60. In step S120, it is determined whether all intermediate ECUs 20 and 30 have finished starting up and have entered normal operation mode. For example, the upper ECU 10 can determine whether all intermediate ECUs 20 and 30 have finished starting up by whether a predetermined time longer than the startup processing time of the intermediate ECU that takes the longest to start up has elapsed. If it is determined that all intermediate ECUs 20 and 30 have not finished starting up, the upper ECU 10 returns to the process in step S110. Therefore, the process in step S110 is repeatedly executed until it is determined that all intermediate ECUs 20 and 30 have finished starting up. As a result, the upper ECU 10 may repeatedly send startup NM messages at predetermined intervals.

[0069] In step S120, if the upper ECU 10 determines that all intermediate ECUs 20 and 30 have been activated, it proceeds to step S130. In step S130, based on the vehicle status, it sends relay control messages instructing the first to third relay circuits 26, 28, and 36 to be turned on or off. With this, the processing of the upper ECU 10 in response to the activation trigger is completed. Thereafter, although not shown in the diagram, the upper ECU 10 repeatedly sends relay control messages at predetermined intervals according to the latest vehicle status.

[0070] In step S200, the first and second intermediate ECUs 20 and 30 perform a startup process to transition from low-power mode to normal operation mode in response to the reception of a startup NM message. After transitioning to normal operation mode through this startup process, the first and second intermediate ECUs 20 and 30 receive startup NM messages repeatedly transmitted at predetermined intervals from the upper ECU 10 in step S210. The first and second intermediate ECUs 20 and 30 then decode the PN request information contained in the received startup NM message and perform relay control processing based on the decoded PN request information. The upper ECU 10 does not need to repeatedly transmit startup NM messages. The first and second intermediate ECUs 20 and 30 can also store the selective startup instructions for the lower ECUs 40, 50, and 60 contained in the received startup NM message.

[0071] In step S220, the first and second intermediate ECUs 20 and 30 determine whether or not they have received a relay control message from the higher-level ECU 10. If they determine that they have received a relay control message, the first and second intermediate ECUs 20 and 30 proceed to the process in step S230. On the other hand, if they determine that they have not received a relay control message, the first and second intermediate ECUs 20 and 30 return to the process in step S210 and continue the relay control process according to the activation NM message.

[0072] In step S230, the first and second intermediate ECUs 20 and 30 perform relay control processing to turn on or off the first to third relay circuits 26, 28, and 36 according to the received relay control message.

[0073] In step S300, when relay control processing is performed by the first and second intermediate ECUs 20 and 30 and the corresponding first to third relay circuits 26, 28, and 36 are turned on, power is supplied to the first to third lower ECUs 40, 50, and 60. In step S310, the first to third lower ECUs 40, 50, and 60, which have been powered on, perform a predetermined startup process. As a result, the first to third lower ECUs 40, 50, and 60 transition to normal operation mode.

[0074] In step S320, the power supply to the first to third lower ECUs 40, 50, and 60 is maintained or stopped by relay control processing in the first and second intermediate ECUs 20 and 30 in accordance with relay control messages.

[0075] As described above, in this embodiment, the NM control master 14 sends a startup NM message to the first and second intermediate ECUs 20 and 30, which are in low-power mode, in response to the occurrence of a startup trigger. This startup NM message allows the first and second intermediate ECUs 20 and 30 to transition from low-power mode to normal operation mode. The startup NM message includes a selective instruction to start the first to third lower ECUs 40, 50, and 60. Therefore, until a relay control message is given by the power control master 16, the first and second intermediate ECUs 20 and 30 can turn the first to third relay circuits 26, 28, and 36 on or off based on the instructions included in the startup NM message. This allows processing to start supplying power to the first to third lower ECUs 40, 50, and 60 even before the relay control message is given to the first and second intermediate ECUs 20 and 30, thereby shortening the time until power supply is started.

[0076] (Second Embodiment) Next, a second embodiment of the in-vehicle network system and control method for the in-vehicle network system according to this disclosure will be described. The in-vehicle network system according to this embodiment is configured in the same way as the in-vehicle network system 100 according to the first embodiment. Therefore, a description of the configuration of the in-vehicle network system according to this embodiment will be omitted.

[0077] In the in-vehicle network system 100 according to this embodiment, as shown in Figure 8, in response to the occurrence of a startup trigger, the higher-level ECU 10 sends a startup NM message to the first and second intermediate ECUs 20 and 30, which are in low-power consumption mode, including a selective instruction (PN request information) to start the first to third lower-level ECUs 40, 50, and 60. This is the same as in the in-vehicle network system 100 according to the first embodiment.

[0078] However, in the in-vehicle network system 100 according to this embodiment, when the first and second intermediate ECUs 20 and 30 transition to normal operation mode in response to a startup NM message, as shown in Figure 8, the first and second intermediate ECUs 20 and 30 turn on the first to third relay circuits 26, 28, and 36 before decoding the selective instructions for activating the first to third lower ECUs 40, 50, and 60 contained in the startup NM message (including startup NM messages received after transitioning to normal operation mode). Figure 8 shows an example in which the first and second intermediate ECUs 20 and 30 turn on the first to third relay circuits 26, 28, and 36 immediately after transitioning to normal operation mode. However, the first and second intermediate ECUs 20 and 30 may turn on the first to third relay circuits 26, 28, and 36 at any timing before decoding the startup NM message.

[0079] Then, after transitioning to the normal operating mode, the first and second intermediate ECUs 20 and 30 execute relay control processing based on the selective activation instructions for the first to third lower ECUs 40, 50, and 60 contained in the activation NM message, as shown in Figure 8. In this relay control processing, first, the selective activation instructions for the first to third lower ECUs 40, 50, and 60 contained in the activation NM message are decoded. That is, the first and second intermediate ECUs 20 and 30 compare the PN request information contained in the activation NM message with the PNC setting information of each of the multiple lower ECUs 40, 50, and 60 bit by bit. Then, based on the comparison result, if the first and second intermediate ECUs 20 and 30 determine that there is PNC setting information that includes a cluster that has been requested to be activated by the PN request information, they determine that the activation of the lower ECUs 40, 50, and 60 corresponding to that PNC setting information has been instructed.

[0080] Furthermore, the first and second intermediate ECUs 20 and 30, as part of relay control processing, refer to relay connection information based on node IDs indicating the lower ECUs 40, 50, and 60 that were instructed to be activated by the activation NM message, and determine which relay circuits should be turned on and which should be turned off. Then, the first and second intermediate ECUs 20 and 30 drive the first and second relay control units 24 and 34 to turn on the relay circuits 26, 28, and 36 that should be turned on, and turn off the relay circuits 26, 28, and 36 that should be turned off.

[0081] As a result, relay circuits 26, 28, and 36 that should be turned on remain turned on. Conversely, relay circuits 26, 28, and 36 that should be turned off are switched from on to off.

[0082] Figure 9 is a flowchart showing an example of processing performed in the upper-level ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower-level ECUs 40, 50, and 60 of the in-vehicle network system 100 according to this embodiment, in response to the occurrence of a startup trigger. In the flowchart of Figure 9, step S205 is added compared to the flowchart of Figure 7. The other steps are the same in the flowcharts of Figure 7 and Figure 9, so their explanation is omitted.

[0083] Step S205 is performed by the first and second intermediate ECUs 20 and 30 after they have transitioned to normal operation mode through the startup process. In step S205, the first and second intermediate ECUs 20 and 30 turn on the first to third relay circuits 26, 28, and 36. That is, after transitioning to normal operation mode, the first and second intermediate ECUs 20 and 30 turn on all relay circuits 26, 28, and 36 regardless of the instructions included in the startup NM message. Subsequently, in step S210, the first and second intermediate ECUs 20 and 30 perform relay control processing according to the startup NM message.

[0084] As described above, according to the in-vehicle network system 100 of this embodiment, the first and second intermediate ECUs 20 and 30 turn on the first to third relay circuits 26, 28, and 36 after transitioning to the normal operating mode and before decoding the selective instructions for starting the first to third lower ECUs 40, 50, and 60 contained in the startup NM message. This allows power supply to the first to third lower ECUs 40, 50, and 60 to start earlier.

[0085] Furthermore, according to the in-vehicle network system 100 of this embodiment, relay control processing is performed based on selective instructions to activate the first to third lower ECUs 40, 50, and 60 included in the startup NM message. As a result, even if the first to third relay circuits 26, 28, and 36 are turned on after transitioning to the normal operation mode, relay circuits 26, 28, and 36 that do not need to be turned on are turned off by the relay control processing. Therefore, the on and off states of the first to third lower ECUs 40, 50, and 60 can be appropriately controlled.

[0086] (modified version) While preferred embodiments of this disclosure have been described above, this disclosure is not limited in any way to the embodiments described above and can be implemented in various modified forms without departing from the spirit of this disclosure.

[0087] (Variation 1) For example, in the embodiment described above, an example was described in which the higher-level ECU 10 has one NM control master 14 and one power supply control master 16. However, considering the occurrence of abnormalities in the NM control master 14 and power supply control master 16, multiple NM control masters 14 and power supply control masters 16 may be provided.

[0088] Figure 10 shows an example of an in-vehicle network system 100A in which a main NM control master 14a and a sub-NM control master 14b, and a main power control master 16a and a sub-power control master 16b are provided in the upper-level ECU 10. Note that if an NM control master is provided in an ECU other than the upper-level ECU 10, multiple NM control masters may be provided.

[0089] When multiple NM control masters 14a, 14b and / or multiple power control masters 16a, 16b are provided, for example, if the main NM control master 14a and / or main power control master 16a are functioning normally, the main NM control master 14a and / or main power control master 16a may send the startup NM message and / or relay control message. If any abnormality occurs in the main NM control master 14a and / or main power control master 16a, the sub-NM control master 14b and / or sub-power control master 16b may send the startup NM message and / or relay control message on behalf of the main NM control master 14a and / or main power control master 16a. In this case, the occurrence of an abnormality in the main NM control master 14a and / or main power control master 16a may be detected by the sub-NM control master 14b and / or sub-power control master 16b, or by a dedicated abnormality detection circuit.

[0090] (Modification 2) In the above-described embodiment, a message authenticator may be added to the activation NM messages and / or relay control messages transmitted from the higher-level ECU 10 or the like to the first and second intermediate ECUs 20 and 30 to authenticate the legitimacy of the messages. This prevents the relay circuits 26, 28, and 36 from being turned on or off by activation NM messages and / or relay control messages that are fraudulently transmitted, for example, through impersonation.

[0091] For example, the higher-level ECU 10 calculates the hash value of the activation NM message and / or relay control message to be transmitted. Then, the higher-level ECU 10 encrypts the hash value with a common key that has been shared in advance with the first and second intermediate ECUs 20 and 30 to calculate the MAC (Message Authentication Code) value as the message authentication value. The higher-level ECU 10 transmits the activation NM message and / or relay control message and the MAC value to the first and second intermediate ECUs 20 and 30.

[0092] The first and second intermediate ECUs 20 and 30 calculate the hash value of the received activation NM message and / or relay control message. Furthermore, the first and second intermediate ECUs 20 and 30 decrypt the received MAC value using a common key and calculate a hash value. If the first and second intermediate ECUs 20 and 30 find that the calculated hash value matches the decrypted hash value, they authenticate the validity of the received activation NM message and / or relay control message.

[0093] (Variation 3) 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 upper ECU 10, the first and second intermediate ECUs 20, 30, and the first to third lower ECUs 40, 50, 60 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 upper ECU 10, the first and second intermediate ECUs 20 and 30, and the first to third lower ECUs 40, 50, and 60 may be implemented using a system-on-a-chip (SoC), integrated circuit (IC), or field-programmable gate array (FPGA). The concept of IC also includes application-specific integrated circuits (ASIC). Furthermore, computer programs only need to be stored on a computer-readable non-transitory tangible storage medium as instructions executed by the computer. Hard disk drives (HDDs), solid state drives (SSDs), flash memory, etc., can be used as the storage medium for programs. Furthermore, the scope of this disclosure also includes programs for causing a computer to function as a higher-level ECU 10, first and second intermediate-level ECUs 20 and 30, and first to third lower-level ECUs 40, 50 and 60, as well as non-transitional physical recording media such as semiconductor memory on which these programs are recorded.

[0094] (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.

[0095] (Technical thought 1) An in-vehicle network system (100) having multiple control devices (10, 20, 30, 40, 50, 60) connected to a communication bus (38, 54, 64) and capable of communicating with each other, The multiple control devices include at least one lower control device (40, 50, 60) and at least one higher-level control device (20, 30) positioned above the lower control device. The aforementioned upper-level control device has a normal operation mode and a low-power consumption mode as operating modes, and also has relay control units (24, 34) that turn on and off relay circuits (26, 28, 36) provided on the power supply line (6) of the lower-level control device. A power control master (16) provides the upper-level control device with a relay control message that instructs the relay circuit to be turned on or off depending on the vehicle status, The system includes an NM control master (14) that transmits a network management (NM) message to the upper-level control device via the communication bus, which selectively instructs the lower-level control device to start up. The NM control master transmits a startup NM message to the upper-level control unit, which is in the low-power mode, in response to the occurrence of a startup trigger that causes the upper-level control unit to enter the normal operating mode, thereby enabling the upper-level control unit to transition to the normal operating mode. The aforementioned startup NM message includes a selective instruction to start the subordinate control device, An in-vehicle network system in which, until the relay control message is provided to the higher-level control device by the power control master, the higher-level control device turns the relay circuit on or off based on the selective instruction to start the lower-level control device contained in the start NM message.

[0096] (Technical thought 2) The in-vehicle network system according to technical concept 1, wherein the power control master provides the relay control message to the upper-level control device according to the vehicle status after the startup of the upper-level control device is completed by the startup NM message and the upper-level control device has transitioned to the normal operation mode.

[0097] (Technical Thought 3) An in-vehicle network system according to technical concept 1 or 2, wherein after the relay control message is provided to the higher-level control device by the power control master, the higher-level control device prioritizes the instructions from the relay control message over the instructions from the startup NM message and turns the relay circuit on or off.

[0098] (Technical Thought 4) The above-ground control device turns the relay circuit on or off based on the instructions given by the activation NM message, and thereafter, upon receiving the relay control message, turns the relay circuit on or off based on the instructions given by the relay control message, in an in-vehicle network system according to any one of technical ideas 1 to 3.

[0099] (Technical Thought 5) The in-vehicle network system according to any one of technical concepts 1 to 4, wherein the NM control master repeatedly transmits the startup NM message at predetermined intervals until the relay control message is provided to the higher-level control device by the power supply control master.

[0100] (Technical Thought 6) The above-level control device is activated by the activation NM message, and when it transitions to the normal operation mode, it decodes the activation NM message received thereafter and turns the relay circuit on or off based on the instructions contained in the activation NM message, in the in-vehicle network system according to technical concept 5.

[0101] (Technical Thought 7) The above-ground control device is activated by the activation NM message, and when it transitions to the normal operation mode, it turns on the relay circuit before decoding the activation NM message or any subsequent activation NM messages, according to any one of technical ideas 1 to 6, in an in-vehicle network system.

[0102] (Technical Thought 8) The above-level control device, after transitioning to the normal operating mode, completes the decoding of the startup NM message, and if the instruction contained in the startup NM message indicates turning off the relay circuit, turns off the relay circuit, as described in Technical Concept 7 of the in-vehicle network system.

[0103] (Technical Thought 9) An in-vehicle network system according to any one of technical ideas 1 to 8, wherein the activation NM message and / or the relay control message are provided with a message authenticator for authenticating the legitimacy of the message.

[0104] (Technical Thought 10) Multiple NM control masters are provided in the in-vehicle network system. An in-vehicle network system according to any one of technical concepts 1 to 9, wherein when the higher-level control device receives the activation NM message from each of the multiple NM control masters, the higher-level control device turns on the relay circuit if any of the activation NM messages instruct the lower-level control device to activate.

[0105] (Technical Thought 11) The above-ground control device, based on the instructions of the activation NM message, turns on the relay circuit for a predetermined time, in the vehicle network system according to any one of Technical Ideas 1 to 10.

[0106] (Technical Thought 12) The in-vehicle network system has a higher-level control device (10) positioned above the higher-level control device, The power control master is an in-vehicle network system according to any one of technical concepts 1 to 11, provided in the higher-level control device.

[0107] (Technical Thought 13) The in-vehicle network system has a plurality of higher-level control devices below the higher-level control device, The in-vehicle network system according to technical concept 12, wherein the power control master individually instructs a plurality of higher-level control devices to turn the relay circuit on or off using the relay control message, depending on the vehicle status. [Explanation of Symbols]

[0108] 2: Battery, 4: Power supply circuit, 6: Power supply line, 10: Higher-level ECU, 12: Communication IF, 14: NM control master, 16: Power control master, 20: 1st intermediate-level ECU, 22: Communication IF, 24: 1st relay control unit, 26: 1st relay circuit, 28: 2nd relay circuit, 30: 2nd intermediate-level ECU, 32: Communication IF, 34: 2nd relay control unit, 36: 3rd relay circuit, 38: Communication bus, 40: 1st lower-level ECU, 42: Communication IF, 44: Communication bus, 50: 2nd lower-level ECU, 52: Communication IF, 54: Communication bus, 60: 3rd lower-level ECU, 62: Communication IF, 64: Communication bus, 100: In-vehicle network system

Claims

1. An in-vehicle network system (100) in a vehicle having a plurality of control devices (10, 20, 30, 40, 50, 60) connected to a communication bus (38, 54, 64) and capable of communicating with each other, The multiple control devices include at least one lower-level control device (40, 50, 60) and at least one higher-level control device (20, 30) positioned above the lower-level control device. The aforementioned upper-level control device has a normal operation mode and a low-power consumption mode as operating modes, and also has relay control units (24, 34) that turn on and off relay circuits (26, 28, 36) provided on the power supply line (6) of the lower-level control device. A power control master (16) provides the upper-level control device with a relay control message that instructs the relay circuit to be turned on or off depending on the vehicle status, The system includes an NM control master (14) that transmits a network management (NM) message to the upper-level control device via the communication bus, which selectively instructs the lower-level control device to start up. The NM control master transmits a startup NM message to the upper-level control unit, which is in the low-power mode, in response to the occurrence of a startup trigger that causes the upper-level control unit to enter the normal operating mode, thereby enabling the upper-level control unit to transition to the normal operating mode. The startup NM message includes a selective instruction to start the lower-level control device. An in-vehicle network system in which, until the relay control message is provided to the higher-level control device by the power control master, the higher-level control device turns the relay circuit on or off based on the selective instruction to start the lower-level control device included in the start NM message.

2. The in-vehicle network system according to claim 1, wherein the power control master provides the relay control message to the upper-level control device according to the vehicle status after the startup of the upper-level control device is completed by the startup NM message and the upper-level control device has transitioned to the normal operation mode.

3. The in-vehicle network system according to claim 1 or 2, wherein after the relay control message is provided to the higher-level control device by the power control master, the higher-level control device prioritizes the instructions from the relay control message over the instructions from the startup NM message and turns the relay circuit on or off.

4. The in-vehicle network system according to claim 1 or 2, wherein the higher-level control device turns the relay circuit on or off based on the instructions given by the startup NM message, and thereafter, upon receiving the relay control message, turns the relay circuit on or off based on the instructions given by the relay control message.

5. The in-vehicle network system according to claim 1 or 2, wherein the NM control master repeatedly transmits the startup NM message at predetermined intervals until the relay control message is provided to the higher-level control device by the power supply control master.

6. The in-vehicle network system according to claim 5, wherein the higher-level control device is activated by the activation NM message, and when it transitions to the normal operation mode, it decodes the activation NM message received thereafter and turns the relay circuit on or off based on the instructions contained in the activation NM message.

7. The in-vehicle network system according to claim 5, wherein the higher-level control device is activated by the activation NM message, and when it transitions to the normal operation mode, it turns on the relay circuit before decoding the activation NM message or any subsequent activation NM messages.

8. The in-vehicle network system according to claim 7, wherein, after transitioning to the normal operation mode, the higher-level control device, upon completion of decoding the startup NM message, turns off the relay circuit if the instruction contained in the startup NM message indicates turning off the relay circuit.

9. The in-vehicle network system according to claim 1 or 2, wherein the activation NM message and / or the relay control message are provided with a message authenticator for authenticating the validity of the message.

10. Multiple NM control masters are provided in the in-vehicle network system. The in-vehicle network system according to claim 1 or 2, wherein when the higher-level control device receives the activation NM message from each of the multiple NM control masters, it turns on the relay circuit if any of the activation NM messages instruct the lower-level control device to activate.

11. The in-vehicle network system according to claim 1 or 2, wherein the higher-level control device, in response to an instruction from the startup NM message, turns on the relay circuit for a predetermined amount of time.

12. The in-vehicle network system has a higher-level control device (10) which is positioned even higher than the higher-level control device, The in-vehicle network system according to claim 1 or 2, wherein the power control master is provided in the higher-level control device.

13. The in-vehicle network system has a plurality of higher-level control devices below the higher-level control device, The in-vehicle network system according to claim 12, wherein the power control master individually instructs a plurality of higher-level control devices to turn on or off the relay circuit using the relay control message, depending on the vehicle status.

14. A control method for an in-vehicle network system (100) having a plurality of control devices (10, 20, 30, 40, 50, 60) connected to a communication bus (38, 54, 64) and capable of communicating with each other, The multiple control devices include at least one lower-level control device (40, 50, 60) and at least one higher-level control device (20, 30) positioned above the lower-level control device. The aforementioned upper-level control device has a normal operation mode and a low-power consumption mode as operating modes, and also has relay control units (24, 34) that turn on and off relay circuits (26, 28, 36) provided on the power supply line (6) of the lower-level control device. The power control master (16) provides the higher-level control device with a relay control message that instructs the relay circuit to be turned on or off according to the vehicle status. The NM control master (14) transmits a network management (hereinafter, NM) message via the communication bus to the upper-level control device, which selectively instructs the lower-level control device to start up. The NM control master transmits a startup NM message to the upper-level control unit, which is in the low-power mode, in response to the occurrence of a startup trigger that causes the upper-level control unit to enter the normal operating mode, thereby enabling the upper-level control unit to transition to the normal operating mode. The startup NM message includes a selective instruction to start the lower-level control device. A control method for an in-vehicle network system, wherein, until the relay control message is provided to the higher-level control device by the power control master, the higher-level control device turns the relay circuit on or off based on the selective instruction to start the lower-level control device included in the start NM message.

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