In-vehicle devices and in-vehicle systems
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DENSO CORP
- Filing Date
- 2025-01-17
- Publication Date
- 2026-07-30
Smart Images
Figure 2026123583000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to an in-vehicle device and an in-vehicle system.
Background Art
[0002] Patent Document 1 below describes an in-vehicle system including a power supply device and a plurality of communication devices. The power supply device and each communication device are connected by a power line extending from the power supply device and branched according to the number of communication devices. A power supply cutoff unit corresponding to each communication device is provided in the branched power line. The power supply cutoff unit cuts off the power supply from the power supply device to the communication device. According to the in-vehicle system of Patent Document 1, since the power supply can be cut off for each communication device, it is also possible to selectively cut off the power supply only for communication devices in a situation where communication is unnecessary.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, as a result of the inventors' detailed examination, the following problems were found. That is, if the power supply cutoff unit fails, there is a possibility that the power supply cannot be cut off. Even in a communication device that is originally in a situation where communication is unnecessary, if the power supply is not cut off, the communication device will perform unnecessary communication.
[0005] One aspect of the present disclosure provides a technique in which a communication device does not perform unnecessary communication even when the power supply to the communication device is not cut off.
Means for Solving the Problems
[0006] One aspect of this disclosure is an in-vehicle device (5, 5a, 5b) used in an in-vehicle system (100, 200, 300, 400) equipped with a plurality of communication devices (1-3, 1a-1f). Each of the plurality of communication devices is configured to receive power through its respective power supply path (21-23). Each power supply path is provided with a power supply switching unit (31-33, 61-69) configured to switch between an ON state, which allows conductivity through the power supply path, and an OFF state, which blocks the power supply path. The in-vehicle device comprises a control unit (53) and a communication unit (54). The control unit is configured to perform switching control, which controls whether to switch the power supply switching unit to the ON state or the OFF state. The communication unit is configured to communicate with the plurality of communication devices. The communication unit also outputs control information, which is information indicating whether the switching control performed by the control unit is a switch to the ON state or a switch to the OFF state, when the switching control is performed by the control unit. Multiple communication devices are configured to stop the transmission process that sends a communication frame when they receive control information output by a communication unit and the control information for themselves indicates a switch to the off state.
[0007] With this configuration, even if the power supply path is not actually interrupted, multiple communication devices can recognize that the power supply switching unit corresponding to each communication device should be switched to the off state. Therefore, the multiple communication devices can simulate the situation when the power supply switching unit is actually switched to the off state and stop the transmission process. Consequently, even if the power supply to the multiple communication devices is not interrupted, the multiple communication devices will not perform unnecessary communications.
[0008] One aspect of this disclosure may be an in-vehicle system (100, 200, 300, 400) on which a plurality of communication devices (1-3, 1a-1f) and in-vehicle devices (5, 5a, 5b) are mounted. [Brief explanation of the drawing]
[0009] [Figure 1] This is a block diagram showing the configuration of the communication system of the embodiment. [Figure 2] This is a block diagram of the electronic control unit. [Figure 3] Figure 3A is a diagram illustrating an example of management information, Figure 3B is a diagram illustrating an example of switching control, and Figure 3C is a diagram illustrating an example of control information. [Figure 4] This is a sequence diagram showing the switching process under normal conditions. [Figure 5] This is a sequence diagram showing the switching process from the ON state to the OFF state when the device is stuck in the ON state. [Figure 6] This is a sequence diagram showing the switching process to the ON state when the device is stuck in the ON position. [Figure 7] This flowchart shows the process when switching control is performed. [Figure 8] This is a flowchart showing the process when stopping the transmission process. [Figure 9] This is a flowchart showing the process when the transmission process is initiated. [Figure 10] This is a block diagram showing the configuration of the communication system in the modified example 1. [Figure 11] This is a block diagram showing the configuration of the communication system in variation 2. [Figure 12] This is a block diagram showing the configuration of the communication system in the modified example 3. [Modes for carrying out the invention]
[0010] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Embodiments] [1-1. Structure] The communication system 100 shown in Figure 1 constitutes a network system installed in a vehicle, such as a passenger car. The communication system 100 is an in-vehicle system equipped with multiple electronic control units (hereinafter referred to as ECUs 1 to 5). The multiple ECUs 1 to 5 are connected to each other via communication lines, enabling data communication. ECU stands for "Electronic Control Unit".
[0011] ECUs 1-5 receive power from a battery 6 mounted in the vehicle via power lines. Battery 6 supplies power at a DC battery voltage (e.g., 12V). Power lines branch off from battery 6 and extend to form power supply paths 21-23. In this embodiment, ECU1 receives power from battery 6 via power supply path 21 between battery 6 and ECU1. ECU2 receives power from battery 6 via power supply path 22 between battery 6 and ECU2. ECU3 receives power from battery 6 via power supply path 23 between battery 6 and ECU3. Power supply paths for ECUs 4 and 5 are not shown in the illustration, but ECUs 4 and 5 also receive power from battery 6.
[0012] ECUs 1-5 are configured to transition between a wake-up state, which is the normal operating state, and a sleep state, which is a low-power operating state in which at least some of their functions are restricted. For example, in the wake-up state, ECUs 1-5 can use all of their functions. On the other hand, in the sleep state, ECUs 1-5 may have functions other than the reception processing described later restricted. ECUs 1-5 transition from the wake-up state to the sleep state if they do not receive a communication request from any of the ECUs. In other words, ECUs 1-5 transition to the sleep state if they do not receive a communication request from any of the ECUs for a predetermined time set in advance. On the other hand, ECUs 1-5 maintain the wake-up state if they receive a communication request from any of the ECUs.
[0013] For example, if power is no longer supplied from battery 6 to each ECU1-5, each ECU1-5 will stop sending communication requests and enter a sleep state. In other words, if all ECU1-5 that make up the communication system 100 stop sending communication requests, all ECU1-5 will stop receiving communication requests, and the entire communication system 100 will enter a low-power state. A communication request represents a request to send a communication frame.
[0014] Power supply paths 21 to 23 are respectively provided with power supply switching units 31 to 33. The power supply switching units 31 to 33 are configured to switch between an on state in which each of the power supply paths 21 to 23 is made conductive and an off state in which each of the power supply paths 21 to 23 is cut off. The power supply switching units 31 to 33 are constituted by, for example, a mechanical relay having mechanical contacts or a semiconductor relay having no mechanical contacts. In the present embodiment, the power supply switching units 31 to 33 are constituted by semiconductor relays such as FETs. When the control unit 53 described later applies a gate voltage to the gate terminal of the FET, the FET switches to the on state. Note that the power supply switching units 31 to 33 may be illustrated as SW31 to 33.
[0015] As shown in FIG. 2, the ECU 1 includes a CPU 11 and a memory 12. A program for the CPU 11 to execute a predetermined function is stored in the memory 12. The ECU 1 realizes functions as the following respective units when the CPU 11 executes the program in the memory 12. That is, the ECU 1 has functions as a communication unit 13 and an abnormality detection unit 14.
[0016] The communication unit 13 is configured to be able to communicate with the ECUs 2 to 5. More specifically, the communication unit 13 executes a transmission process for transmitting a communication frame and a reception process for receiving a communication frame. When the communication unit 13 acquires the control information output by the communication unit 54 of the ECU 5 described later and the control information about itself is a switch to the off state, the communication unit 13 is configured to stop the transmission process. On the other hand, when the communication unit 13 acquires the control information output by the communication unit 54 of the ECU 5 and the control information about itself is a switch to the on state, the communication unit 13 is configured to start the transmission process.
[0017] The anomaly detection unit 14 is configured to perform communication anomaly detection (hereinafter also referred to as anomaly detection processing) to detect whether or not there is an anomaly in the communication state of the communication system 100. For example, as a communication anomaly detection, the anomaly detection unit 14 performs a disconnection determination to determine whether or not communication frames that should be received from other ECUs have been interrupted. More specifically, if the state in which communication frames transmitted from other ECUs have not been received continues for a predetermined communication anomaly determination time (for example, 2 seconds), the anomaly detection unit 14 determines that a communication anomaly has occurred with other ECUs and that there is an anomaly in the communication state of the communication system.
[0018] When the abnormality detection unit 14 acquires control information output by the communication unit 54 of the ECU 5, it stops detecting communication abnormalities if the control information for itself is switched to the off state. On the other hand, when the abnormality detection unit 14 acquires control information output by the communication unit 54 of the ECU 5, it starts detecting communication abnormalities if the control information for itself is switched to the on state.
[0019] Although the block diagrams for ECU2 and ECU3 are not shown, they have the same configuration as ECU1. Returning to Figure 1, the ECU 4 comprises a CPU 41 and a memory 42. The memory 42 stores a program for the CPU 41 to perform a predetermined function.
[0020] The ECU4 performs the following functions by having the CPU 41 execute the program in the memory 42. Specifically, the ECU4 includes the functions of a power state management unit 43 and a communication unit 44.
[0021] The power state management unit 43 is configured to manage whether each power supply switching unit 31 to 33 should transition to the ON state or the OFF state according to the vehicle's driving state. As an example, as shown in Figure 3A, the power state management unit 43 preclassifies the power state and manages it as management information. Management information is information indicating whether the power supply switching units 31 to 33 should transition to the ON state or the OFF state. For example, a rule is predefined that state A indicates a state in which power is supplied to ECU1 and ECU2, but not to ECU3. In other words, state A indicates that power supply switching units 31 and 32 should transition to the ON state, but power supply switching unit 33 should transition to the OFF state.
[0022] For example, a rule is pre-defined that state B indicates a state where power is supplied to ECU2, but not to ECU1 and ECU3. In other words, state B indicates that the power supply switching unit 32 should transition to the ON state, but the power supply switching units 31 and 33 should transition to the OFF state. For example, a rule is pre-defined that state C indicates that power is supplied to ECU1-3. In other words, state C indicates that the power supply switching units 31-33 should transition to the ON state.
[0023] For example, the power state management unit 43 manages the relationship between the vehicle's driving state and a state, such as determining that when the driving state changes from one where cruise control is active to one where cruise control is deactivated, it should change from state B to state C.
[0024] The communication unit 44 is configured to communicate with ECUs 1-3 and 5. The power status management unit 43 notifies the control unit 53 of ECU 5, which will be described later, of the management information via the communication unit 44. The ECU 5 comprises a CPU 51 and a memory 52. The memory 52 stores a program that allows the CPU 51 to perform a predetermined function.
[0025] The ECU 5 performs the following functions by having the CPU 51 execute the program in the memory 52. Specifically, the ECU 5 includes the functions of a control unit 53 and a communication unit 54.
[0026] The control unit 53 is configured to perform switching control to control whether to switch the power supply switching units 31-33 to the ON state or the OFF state. The control unit 53 performs switching control according to the management information notified by the power supply state management unit 43. As shown in Figure 3B, the case in which state A is notified as management information will be explained as an example. In the case of state A, a rule is set in advance to switch the power supply switching unit 31 and power supply switching unit 32 to the ON state and switch the power supply switching unit 33 to the OFF state. The control unit 53 applies gate voltage to the gate terminals of the power supply switching unit 31 and power supply switching unit 32. On the other hand, the control unit 53 stops applying gate voltage to the gate terminal of the power supply switching unit 33.
[0027] Similarly, when state B is notified, the rule is set to switch the power supply switching unit 32 to the ON state and switch the power supply switching units 31 and 33 to the OFF state. When state C is notified, the rule is set to switch the power supply switching units 31, 32, and 33 to the ON state. The control unit 53 performs switching control according to the type of state notified by the power supply state management unit 43.
[0028] Furthermore, the control unit 53 instructs the communication unit 54 to output control information. Control information is information indicating whether the switching control performed by the control unit 53 is a switch to the ON state or an OFF state. For example, as shown in Figure 3C, the communication frame that notifies the control information has the first upper bit of the data field linked to the power supply switching unit 31, the second upper bit linked to the power supply switching unit 32, and the third upper bit linked to the power supply switching unit 33. If the bit value is "1", it indicates that the control unit 53 has performed switching control to switch the power supply switching unit to the ON state, and if the bit value is "0", it indicates that the control unit 53 has performed switching control to switch the power supply switching unit to the OFF state.
[0029] In this case, even if the control unit 53 stops applying the gate voltage to the gate terminal, an abnormality may occur in which the power supply switching unit does not switch to the off state but remains in the on state (hereinafter also referred to as "on-fixed").
[0030] However, the control unit 53 instructs the communication unit 54 to output control information about the switching control performed by the control unit 53, regardless of how the power supply switching units 31 to 33 actually switched. In other words, even if the control unit 53 performed switching control to switch the power supply switching unit to the off state, but in reality an abnormality occurred where the power supply switching unit was stuck on and did not switch to the off state, the control unit 53 instructs the communication unit 54 to output control information indicating that it performed switching control to switch to the off state.
[0031] Furthermore, even if the control unit 53 performs switching control to switch the power supply switching unit to the ON state, but in reality an abnormality of the power supply switching unit being stuck in the ON state occurs, and the power supply switching unit has been in the ON state all along even before the switching control was performed, the control unit 53 instructs the communication unit 54 to output control information indicating that switching control to switch to the ON state has been performed. The communication unit 54 is configured to communicate with ECUs 1 to 4. When switching control is performed by the control unit 53, the communication unit 54 outputs control information acquired from the control unit 53.
[0032] [1-2. Processing] [1-2-1. Processing under normal circumstances] The process performed in the communication system 100 (hereinafter referred to as the switching process) will be explained using the sequence diagram in Figure 4. First, an overview of the switching process under normal conditions will be explained. That is, an overview of the switching process when none of the power supply switching units 31 to 33 are stuck in the ON position will be explained. This switching process is repeatedly performed at a predetermined interval while the power supply state management unit 43 is operating. This switching process may also be performed whenever the vehicle's driving state changes and a situation arises where the power supply state needs to be changed.
[0033] First, in S101, the power state management unit 43 grasps the power state. More specifically, the power state management unit 43 determines which state to transition to according to the vehicle's driving status.
[0034] Next, in S102, the power state management unit 43 notifies the control unit 53 of the management information. More specifically, the power state management unit 43 notifies the control unit 53 of the state determined in S101. Next, in S103, the control unit 53 acquires management information. Furthermore, since the control unit 53 retains management information previously notified by the power status management unit 43, it updates the retained management information when new management information is notified.
[0035] Next, in S104, the control unit 53 performs switching control according to the management information. More specifically, it performs switching control of each power supply switching unit 31 to 33 according to the state value. If a switch to the ON state is performed, as in S105, the power supply path becomes conductive, as in S106. Then, as in S107, the ECUs 1 to 3 corresponding to the power supply switching units 31 to 33 that have been switched to the ON state are powered on. The powered-on ECUs 1 to 3 transition from sleep state to wake-up state and begin transmission processing.
[0036] On the other hand, if a switch to the off state is performed, as in S108, the power supply path is cut off, as in S109. Then, as in S110, the ECUs 1 to 3 corresponding to the power supply switching units 31 to 33 that have been switched to the off state are de-energized. With power de-energized, the ECUs 1 to 3 transition from the wake-up state to the sleep state and stop the transmission process.
[0037] Next, in S111, the communication unit 54 notifies control information. In S112, the ECUs 1 to 3 corresponding to the power supply switching units 31 to 33 that have been switched to the ON state are notified that the switching control performed by the control unit 53 is a switch to the ON state. On the other hand, in S113, the ECUs 1 to 3 corresponding to the power supply switching units 31 to 33 that have been switched to the OFF state are notified that the switching control performed by the control unit 53 is a switch to the OFF state. Note that ECU 5 notifies control information regardless of whether or not the power supply switching units 31 to 33 are stuck in the ON state. Also, under normal circumstances, even if control information is notified, ECUs 1 to 3 do not perform any special processing.
[0038] [1-2-2. Switching process to the OFF state when the ON state is stuck] The sequence diagram in Figure 5 will be used to explain the general process of switching to the off state when the unit is stuck in the on state. This sequence diagram is explained assuming that the power supply switching unit 33 is stuck in the on state.
[0039] First, in S201, the power state management unit 43 determines the power state. For example, the power state management unit 43 decides that it should transition to state A. Next, in S202, the power state management unit 43 notifies the control unit 53 of the management information. For example, the power state management unit 43 notifies the control unit 53 of state A, which was determined in S201.
[0040] Next, in S203, the control unit 53 acquires management information. The control unit 53 also updates the currently held management information with the new management information. Next, in S204, the control unit 53 performs switching control according to the management information. Specifically, the control unit 53 performs switching control of each power supply switching unit 31 to 33 according to the value of State A.
[0041] As shown in S205, the control unit 53 performs a switch to the off state for the power supply switching unit 33. However, as shown in S206, the power supply switching unit 33 is stuck in the ON position. Therefore, the power supply path 23 is not interrupted, and as shown in S211, the ECU 3 remains powered. Normally, the transmission process should stop when the power supply to the ECU 3 is stopped, but because the ECU 3 remains powered, as shown in S209, the ECU 3 continues the transmission process.
[0042] In S207, the communication unit 54 notifies control information. Specifically, as in S208, it notifies the ECU 3 that the switching control performed by the control unit 53 on the power supply switching unit 33 is a switch to the off state.
[0043] ECU3 receives control information indicating that the switching control performed on the power supply switching unit 33 is a switch to the off state, and therefore stops the transmission process as in S210. In other words, ECU3 stops the transmission process even if power is still supplied to ECU3. As a result, the transmission process, which would normally have stopped when power to ECU3 was stopped, is stopped. Note that ECU3 does not stop the reception process. This is because, as will be explained in detail later, it may receive a notification from the control unit 53 indicating that the switching control performed on the power supply switching unit 33 is a switch to the on state, and may resume the transmission process.
[0044] [1-2-3. Switching process to the ON state when the ON state is stuck] The sequence diagram in Figure 6 will be used to explain the general process of switching to the ON state when the ON state is stuck. This sequence diagram assumes that the power supply switching unit 33 is stuck in the ON state. It also assumes the state after steps S208 and S210 of the sequence diagram in Figure 5 have been executed. In other words, it assumes that the power supply switching unit 33 is stuck in the ON state, the power supply path 23 is not interrupted, the ECU 3 is energized, but the transmission process has been stopped.
[0045] First, when the vehicle's driving condition changes and a situation arises where the power supply state should be changed, in S301, the power supply state management unit 43 determines the new power supply state. For example, the power supply state management unit 43 decides that the system should transition to state C.
[0046] Next, in S302, the power state management unit 43 notifies the control unit 53 of the management information. For example, the power state management unit 43 notifies the control unit 53 of state C determined in S301. Next, in S303, the control unit 53 acquires management information. The control unit 53 also updates the currently held management information with the new management information.
[0047] Next, in S304, the control unit 53 performs switching control according to the management information. Specifically, the control unit 53 performs switching control of each power supply switching unit 31 to 33 according to the value of state C.
[0048] As shown in S305, the control unit 53 switches the power supply switching unit 33 to the ON state. Here, as shown in S306, the power supply switching unit 33 remains stuck in the ON position. Therefore, the power supply path 23 is not interrupted, and as shown in S311, the ECU 3 remains energized. Normally, as the power supply to the ECU 3 transitions from stopped to started, the transmission process should also change from stopped to started, but as described in the premise, the ECU 3 is energized and the transmission process is stopped (S309).
[0049] In S307, the communication unit 54 notifies control information. Specifically, as in S308, it notifies the ECU 3 that the switching control performed by the control unit 53 on the power supply switching unit 33 is a switch to the ON state.
[0050] Since ECU3 has received control information that the switching control performed on the power supply switching unit 33 is a switch to the ON state, it resumes the transmission process as in S310. As a result, the transmission process that would normally start when power is supplied to ECU3 begins starts.
[0051] [1-2-4. Processing when executing switching control] The flowchart in Figure 7 illustrates the process when the ECU 5 performs switching control. This process is executed each time management information is notified from the power state management unit 43.
[0052] First, in S401, the control unit 53 obtains management information from the power status management unit 43 via the communication unit 54. Next, in S402, the control unit 53 performs switching control of each power supply switching unit 31 to 33 according to the management information. Next, at S403, the communication unit 54 notifies control information. After that, the ECU 5 terminates this process.
[0053] [1-2-5. Processing when stopping the transmission process] The flowchart in Figure 8 illustrates the process when ECUs 1-3 receive control information and stop the transmission process. This process is repeatedly executed while the transmission process and anomaly detection process are ongoing.
[0054] First, in S501, ECUs 1-3 determine whether or not they have received control information. For example, ECUs 1-3 determine that they have received control information if they receive a communication frame with a pre-set communication ID.
[0055] If ECU1-3 determines in S501 that it has not received control information, it returns to the beginning of this process. On the other hand, if ECU1-3 determines in S501 that it has received control information, it proceeds to S502.
[0056] In S502, ECUs 1-3 determine whether the control information for themselves indicates a switch to the off state. Specifically, ECUs 1-3 check whether the bit in the data field corresponding to their own ECU in the communication frame notifying the control information is "1" (i.e., a switch to the on state) or "0" (i.e., a switch to the off state).
[0057] If ECU1-3 determines in S502 that the control information for itself is not switching to the off state (in other words, if it determines that it is switching to the on state), it returns to the beginning of this process. This is because, in the case of a switch to the on state, the transmission process and abnormality detection process should continue as is.
[0058] On the other hand, if ECU1-3 determines in S502 that the control information for itself is being switched to the off state, it proceeds to S503. At S503, ECUs 1-3 stop the transmission process.
[0059] Next, in S504, ECU1-3 also stops the anomaly detection process. Like the transmission process, the anomaly detection process is a process that should not be executed when the power is cut off (in other words, when in sleep mode). Furthermore, executing the anomaly detection process at a time when it should not be executed could lead to a false positive. Therefore, from the perspective of not executing unnecessary processes, the anomaly detection process is also stopped.
[0060] [1-2-6. Processing when starting the transmission process] The flowchart in Figure 9 illustrates the process when ECUs 1-3 receive control information and begin transmission processing. This process is repeatedly executed while transmission processing and abnormality detection processing are stopped.
[0061] First, in S601, ECU1-3 determine whether or not they have received control information. If ECU1-3 determines in S601 that it has not received control information, it returns to the beginning of this process. On the other hand, if ECU1-3 determines in S601 that it has received control information, it proceeds to S602.
[0062] In S602, ECU1-3 determine whether the control information for themselves indicates a switch to the ON state. If ECU1-3 determines in S602 that the control information for itself is not a switch to the ON state (in other words, if it determines that it is a switch to the OFF state), it returns to the beginning of this process. This is because, in the case of a switch to the OFF state, the transmission process and abnormality detection process should be stopped at this point.
[0063] On the other hand, if ECU1-3 determines in S602 that the control information for itself is a switch to the ON state, it proceeds to S603. In S603, ECU1-3 begin the transmission process. Next, at S604, ECUs 1-3 also begin the anomaly detection process. This is because, ideally, the anomaly detection process should be executed at the same time as the transmission process.
[0064] [1-3. Effects] According to the embodiments described in detail above, the following effects can be obtained.
[0065] (1a) When switching control is performed by the control unit 53, the communication unit 54 outputs control information that indicates whether the switching control performed by the control unit 53 is a switch to the ON state or a switch to the OFF state. When ECUs 1 to 3 receive the control information output by the communication unit 54, they are configured to stop the transmission process that sends a communication frame if the control information for themselves indicates a switch to the OFF state. With this configuration, even if the power supply path is not actually interrupted, ECUs 1 to 3 can recognize that the power supply switching units 31 to 33 corresponding to ECUs 1 to 3 should be switched to the OFF state. Therefore, ECUs 1 to 3 can stop the transmission process as if the power supply switching units 31 to 33 had actually been switched to the OFF state. Consequently, even if the power supply to ECUs 1 to 3 is not interrupted, ECUs 1 to 3 will not perform unnecessary communications.
[0066] (1b) When ECU1~3 acquires control information output by the communication unit 54, if the control information for itself indicates a switch to the off state, it stops the transmission process and also stops the communication anomaly detection by the anomaly detection unit 14. With this configuration, similar to the transmission process, it is possible to stop communication anomaly detection, which would not normally be performed when the power supply paths 21~23 are interrupted. Therefore, similar to the transmission process, ECU1~3 will not perform unnecessary processing. Furthermore, if communication anomaly detection is performed at a time when it should not be performed, it may lead to a false positive. However, since ECU1~3 does not perform unnecessary communication anomaly detection, false positives can be suppressed.
[0067] (1c) When ECU1~3 acquires control information output by the communication unit 54, if the control information for itself indicates a switch to the ON state, it starts the transmission process and the abnormality detection unit 14 starts detecting communication abnormalities. With this configuration, even if the transmission process and communication abnormality detection are stopped when the power supply switching units 31~33 are stuck in the ON state, the transmission process and communication abnormality detection can be restarted. Therefore, at the timing when the transmission process and communication abnormality detection should be performed, ECU1~3 can appropriately perform the transmission process and communication abnormality detection.
[0068] (1d) ECUs 1-5 have a wake-up state and a sleep state. ECUs 1-5 are configured to transition to the sleep state if they do not receive a communication request from any of the other ECUs. If the power supply switching units 31-33 are stuck on, and ECUs 1-3 cannot stop the transmission process, they will send a communication request, preventing the other ECUs constituting the communication system 100 from transitioning to the sleep state. Therefore, the power consumption of the communication system 100 is not reduced. Battery drain may also occur. However, with the above configuration, even if the power supply switching units 31-33 are stuck on, ECUs 1-3 can stop the transmission process. Therefore, ECUs 1-3 will also stop sending communication requests. If all ECUs 1-5 constituting the communication system 100 can stop the transmission process, all ECUs 1-5 will stop sending communication requests, and ECUs 1-5 can transition to the sleep state. Therefore, the power consumption of the communication system 100 can be reduced.
[0069] [1-4. Correspondence] In the above embodiment, ECUs 1 to 3 correspond to multiple communication devices, and ECU 5 corresponds to an in-vehicle device.
[0070] [2. Other Embodiments] While embodiments of this disclosure have been described above, it goes without saying that this disclosure is not limited to the embodiments described above and can take various forms.
[0071] (2a) In the above embodiment, a configuration in which the power supply switching units 31 to 33 are provided outside the ECU 5 was illustrated. However, as shown in the communication system 200 of Modification 1 in Figure 10, for example, the power supply switching units 31 to 33 may be provided inside the ECU 5.
[0072] (2b) In the above embodiment, an example was given in which the ECU 4 is equipped with a power state management unit 43. However, for example, as shown in the communication system 300 of Modification 2 in Figure 11, the power state management unit 43 may be equipped in the ECU 5. In other words, the power state management unit 43 and the control unit 53 may be equipped in the same ECU. If the power state management unit 43 and the control unit 53 are equipped in different ECUs and communication between the ECUs becomes impossible, the control unit 53 will not be able to obtain management information from the power state management unit 43. However, according to the communication system 300 of Modification 2, since the power state management unit 43 and the control unit 53 are equipped in the same ECU, the control unit 53 can obtain management information from the power state management unit 43 without communication.
[0073] (2c) Alternatively, as shown in the communication system 400 of the modified example 3 in Figure 12, for example, the ECU 5 may include both a power supply switching unit and a power supply state management unit 43. Furthermore, the communication system may be equipped with multiple ECUs, each containing a control unit 53.
[0074] In the communication system 400, each control unit 53 controls a different power supply switching unit. For example, the control unit 53 of ECU 5 controls power supply switching units 61-63, the control unit 53 of ECU 5a controls power supply switching units 64-66, and the control unit 53 of ECU 5b controls power supply switching units 67-69. Whether power supply switching units 61-69 should transition to the ON state or the OFF state is centrally managed by the power state management unit 43 of ECU 5.
[0075] The power supply switching unit 61 is configured to switch between the on and off states in each power supply path between the battery 6 and the power supply switching units 64 to 66. The power supply switching unit 62 is configured to switch between the on and off states in the power supply path between the battery 6 and the ECU 1e. The power supply switching unit 63 is configured to switch between the on and off states in the power supply path between the battery 6 and the ECU 1d.
[0076] The power supply switching unit 64 is configured to switch between an on state and an off state in the power supply path between the battery 6 and the ECU 1a. The power supply switching unit 65 is configured to switch between an on state and an off state in the power supply path between the battery 6 and the ECU 1b. The power supply switching unit 66 is configured to switch between an on state and an off state in the power supply path between the battery 6 and the ECU 1c.
[0077] The power supply switching unit 67 is configured to switch between an on state and an off state in the power supply path between the battery 6 and the ECU 1f. Note that the ECUs corresponding to the power supply switching units 68 and 69 are not shown.
[0078] (2d) Each device (i.e., ECU1 to 5) and each method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, each device and each method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, each device and each method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. The methods for implementing the functions of each part included in each device do not necessarily need to include software, and all of its functions may be implemented using one or more hardware components.
[0079] (2e) The functions of one component in the above embodiment may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, some parts of the configuration of the above embodiment may be omitted. Also, at least some parts of the configuration of the above embodiment may be added to, replaced with, or otherwise adapted to the configuration of other above embodiments.
[0080] (2f) The present disclosure can be implemented in various forms, including, in addition to the above-mentioned in-vehicle device, a system that uses the in-vehicle device as a component, a program for causing the computer to function as the in-vehicle device, a medium on which the program is recorded, and a method for switching processes.
[0081] [Technical concepts disclosed in this specification] [Item 1] An in-vehicle device (5, 5a, 5b) used in an in-vehicle system (100, 200, 300, 400) equipped with multiple communication devices (1-3, 1a-1f), Each of the aforementioned communication devices is configured to receive power through its respective power supply path (21-23). Each of the aforementioned power supply paths is provided with a power supply switching unit (31-33, 61-69) configured to switch between an ON state that allows conductivity to the respective power supply path and an OFF state that blocks the respective power supply path. The in-vehicle device is A control unit (53) is configured to perform switching control to control whether to switch the power supply switching unit to the ON state or the OFF state, A communication unit (54) configured to communicate with the aforementioned plurality of communication devices, Equipped with, When the switching control is executed by the control unit, the communication unit outputs control information which indicates whether the switching control executed by the control unit is a switch to the ON state or a switch to the OFF state. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself is a switch to the off state, it stops the transmission process that transmits a communication frame.
[0082] [Item 2] The in-vehicle device described in item 1, The in-vehicle device includes a power state management unit (43), The power supply state management unit is configured to manage whether the power supply switching unit should transition to the ON state or the OFF state according to the vehicle's driving state, and to notify the control unit of management information which indicates whether the power supply switching unit should transition to the ON state or the OFF state. The control unit is an in-vehicle device that performs the switching control in accordance with the management information notified by the power state management unit.
[0083] [Item 3] An in-vehicle device as described in item 1 or item 2, The plurality of communication devices include an abnormality detection unit (14) configured to perform communication abnormality detection to detect whether or not there is an abnormality in the communication state of the in-vehicle system. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself indicates a switch to the off state, in addition to stopping the transmission process, the abnormality detection unit also stops detecting communication abnormalities.
[0084] [Item 4] An in-vehicle device described in any one of items 1 to 3, The plurality of communication devices include an abnormality detection unit (14) configured to perform communication abnormality detection to detect whether or not there is an abnormality in the communication state of the in-vehicle system. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself is a switch to the ON state, it starts the transmission process and starts detecting a communication abnormality by the abnormality detection unit.
[0085] [Item 5] An in-vehicle device described in any one of items 1 through 4, The aforementioned plurality of communication devices and the in-vehicle device are It has a wake-up state, which is the normal operating state, and a sleep state, which is a low-power operating state in which at least some of its functions are limited. The above-mentioned plurality of communication devices and the in-vehicle device are configured to transition to the sleep state if no communication request is received from any of the above-mentioned plurality of communication devices and the in-vehicle device.
[0086] [Item 6] An in-vehicle system (100, 200, 300, 400) is equipped with multiple communication devices (1-3, 1a-1f) and in-vehicle devices (5, 5a, 5b), Each of the aforementioned communication devices is configured to receive power through its respective power supply path (21-23). Each of the aforementioned power supply paths is provided with a power supply switching unit (31-33, 61-69) configured to switch between an ON state that allows conductivity to the respective power supply path and an OFF state that blocks the respective power supply path. The aforementioned in-vehicle device is A control unit (53) is configured to perform switching control to control whether to switch the power supply switching unit to the ON state or the OFF state, A communication unit (54) configured to communicate with the aforementioned plurality of communication devices, Equipped with, When the switching control is executed by the control unit, the communication unit outputs control information which indicates whether the switching control executed by the control unit is a switch to the ON state or a switch to the OFF state. An in-vehicle system in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself indicates a switch to the off state, it stops the transmission process that transmits a communication frame. [Explanation of symbols]
[0087] 1-3, 5, 1a-1f, 5a, 5b...ECU, 21-23...Power supply path, 31-33, 61-69...Power supply switching unit, 53...Control unit, 54...Communication unit, 61...Power supply switching unit, 100, 200, 300, 400...Communication system.
Claims
1. An in-vehicle device (5, 5a, 5b) used in an in-vehicle system (100, 200, 300, 400) equipped with multiple communication devices (1-3, 1a-1f), Each of the aforementioned communication devices is configured to receive power through its respective power supply path (21-23). Each of the aforementioned power supply paths is provided with a power supply switching unit (31-33, 61-69) configured to switch between an ON state that allows conductivity to the respective power supply path and an OFF state that blocks the respective power supply path. The in-vehicle device is A control unit (53) is configured to perform switching control to control whether to switch the power supply switching unit to the ON state or the OFF state, A communication unit (54) configured to communicate with the aforementioned plurality of communication devices, Equipped with, When the switching control is executed by the control unit, the communication unit outputs control information which indicates whether the switching control executed by the control unit is a switch to the ON state or a switch to the OFF state. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself is a switch to the off state, it stops the transmission process that transmits a communication frame.
2. The in-vehicle device according to claim 1, The in-vehicle device includes a power state management unit (43), The power supply state management unit is configured to manage whether the power supply switching unit should transition to the ON state or the OFF state according to the vehicle's driving state, and to notify the control unit of management information which indicates whether the power supply switching unit should transition to the ON state or the OFF state. The control unit is an in-vehicle device that performs the switching control in accordance with the management information notified by the power state management unit.
3. An in-vehicle device according to claim 1 or claim 2, The plurality of communication devices include an abnormality detection unit (14) configured to perform communication abnormality detection to detect whether or not there is an abnormality in the communication state of the in-vehicle system. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself indicates a switch to the off state, in addition to stopping the transmission process, the abnormality detection unit also stops detecting communication abnormalities.
4. An in-vehicle device according to claim 1 or claim 2, The plurality of communication devices include an abnormality detection unit (14) configured to perform communication abnormality detection to detect whether or not there is an abnormality in the communication state of the in-vehicle system. An in-vehicle device in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself is a switch to the ON state, it starts the transmission process and starts detecting a communication abnormality by the abnormality detection unit.
5. An in-vehicle device according to claim 1 or claim 2, The aforementioned plurality of communication devices and the in-vehicle device are It has a wake-up state, which is the normal operating state, and a sleep state, which is a low-power operating state in which at least some of its functions are limited. The above-mentioned plurality of communication devices and the in-vehicle device are configured to transition to the sleep state if no communication request is received from any of the above-mentioned plurality of communication devices and the in-vehicle device.
6. An in-vehicle system (100, 200, 300, 400) is equipped with multiple communication devices (1-3, 1a-1f) and in-vehicle devices (5, 5a, 5b), Each of the aforementioned communication devices is configured to receive power through its respective power supply path (21-23). Each of the aforementioned power supply paths is provided with a power supply switching unit (31-33, 61-69) configured to switch between an ON state that allows conductivity to the respective power supply path and an OFF state that blocks the respective power supply path. The aforementioned in-vehicle device is A control unit (53) is configured to perform switching control to control whether to switch the power supply switching unit to the ON state or the OFF state, A communication unit (54) configured to communicate with the aforementioned plurality of communication devices, Equipped with, When the switching control is executed by the control unit, the communication unit outputs control information which indicates whether the switching control executed by the control unit is a switch to the ON state or a switch to the OFF state. An in-vehicle system in which, when the plurality of communication devices acquire the control information output by the communication unit, if the control information for itself indicates a switch to the off state, it stops the transmission process that transmits a communication frame.