In-vehicle system

Abstract

An in-vehicle system (10) is provided with a first ECU (11), a second ECU (12), and a third ECU (13), which are all connected to the same bus (20). When an activation condition is satisfied, the first ECU (11) transitions from a sleep state to an active state, transmits a first activation signal for causing transition of the second ECU (12) to an active state, and then transitions to the sleep state. When the first activation signal has been transmitted to the bus (20), the second ECU (12) is activated while the third ECU (13) is maintained in a sleep state. Upon receiving the first activation signal, the second ECU (12) performs processing based on information included in the first activation signal.

Description

In-vehicle systems

[0001] The present disclosure relates to in-vehicle systems.

[0002] Japanese Patent Application Laid-Open No. 2003-124222 discloses an in-vehicle device that distributes update data provided from outside the vehicle to a plurality of ECUs connected via a communication bus.

[0003] Japanese Patent Application Laid-Open No. 2023-152421

[0004] In Patent Document 1, multiple ECUs support the partial network function. Therefore, in order to reduce power consumption, the in-vehicle device can wake up only some of the ECUs used for control and put the other ECUs into sleep mode. However, in the configuration of Patent Document 1, the in-vehicle device is always in an active state, so it is desirable to reduce the power consumption of the in-vehicle device.

[0005] The present disclosure provides a technology that makes it easy to reduce power consumption in a device that can activate only some ECUs to perform a predetermined operation.

[0006] The in-vehicle system of the present disclosure comprises a first ECU, a second ECU, and a third ECU connected to the same bus, wherein the first ECU transitions from a sleep state to an active state when an activation condition is met, transmits a first activation signal to activate the second ECU, and then transitions to the sleep state, and when the first activation signal is transmitted to the bus, the second ECU transitions to an active state while the third ECU remains in a sleep state, and when the second ECU receives the first activation signal, it performs processing based on information contained in the first activation signal.

[0007] According to the technology of the present disclosure, it is easy to reduce the power consumption of a device that can activate only some of the ECUs to perform a predetermined operation.

[0008] Fig. 1 is a schematic diagram showing a vehicle equipped with an in-vehicle system according to a first embodiment. Fig. 2 is a schematic diagram showing the in-vehicle system according to the first embodiment. Fig. 3 is a sequence diagram showing an example of the operation of a first ECU, a second ECU, and a third ECU.

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0010] [1] An in-vehicle system comprising a first ECU, a second ECU, and a third ECU connected to the same bus, wherein the first ECU transitions from a sleep state to an active state when an activation condition is met, transmits a first activation signal to activate the second ECU, and then transitions to the sleep state, and when the first activation signal is transmitted to the bus, the second ECU transitions to an active state while the third ECU is maintained in a sleep state, and when the second ECU receives the first activation signal, performs processing based on information contained in the first activation signal.

[0011] The first ECU switches to an active state when an activation condition is met and transmits a first activation signal. When the first activation signal is transmitted to the bus, the second ECU transitions to an active state while the third ECU remains in a sleep state. The second ECU then performs processing based on information contained in the first activation signal. Furthermore, the first ECU transitions to a sleep state after transmitting the first activation signal. Therefore, the in-vehicle system can easily reduce the power consumption of the first ECU, which can transition only some ECUs, including the second ECU, to an active state to perform a predetermined operation.

[0012] [2] The in-vehicle system described in [1], wherein, when the second ECU receives the first activation signal, it performs processing based on the information contained in the first activation signal, transmits a second activation signal that transitions the third ECU to an activated state, and then transitions to a sleep state; when the second activation signal is transmitted to the bus, the third ECU transitions to an activated state while the first ECU is maintained in a sleep state; and when the third ECU receives the second activation signal, it performs processing based on the information contained in the second activation signal.

[0013] In the in-vehicle system, the second activation signal transmitted from the second ECU causes the third ECU to transition to an activated state and perform processing based on information contained in the second activation signal. Moreover, even when the second activation signal is transmitted, the first ECU does not transition to an activated state, thereby reducing power consumption caused by the first ECU transitioning to an activated state.

[0014] [3] The in-vehicle system described in [2], wherein the first ECU has a wireless communication unit that receives key information transmitted from a key device, the first ECU transitions from a sleep state to an active state when it receives the key information, transmits the first activation signal including the key information, and then transitions to the sleep state, and when the first activation signal is transmitted to the bus, the second ECU transitions to an active state while the third ECU is maintained in a sleep state, and when the second ECU receives the first activation signal, it determines whether authentication is successful based on the key information included in the first activation signal, and if it determines that authentication is successful, it transmits the second activation signal and then transitions to the sleep state.

[0015] The in-vehicle system can reduce power consumption, transition the first ECU to an active state in response to reception of key information, and have the second ECU determine whether authentication has been successful. If authentication is successful, the in-vehicle system can transition the third ECU to an active state and transition the second ECU to a sleep state.

[0016] [4] The first start-up signal includes a first start-up signal and a first information signal; when transmitting the first start-up signal, the first ECU transmits the first information signal after transmitting the first start-up signal; when the first start-up signal is transmitted to the bus, the second ECU transitions to an activated state while the third ECU is maintained in a sleep state; and when the second ECU receives the first information signal in the activated state, the second ECU performs processing based on information contained in the first information signal. An in-vehicle system described in any one of [1] to [3].

[0017] In the above-described in-vehicle system, when the first ECU transmits the first activation signal, the first information signal is transmitted after transmitting the first activation signal, so that the first information signal can be provided to the second ECU that has transitioned to an activated state in response to the first activation signal. With this configuration, the second ECU does not need to store information necessary for executing processing before transitioning to an activated state.

[0018] [5] The first activation signal includes a first activation signal and a first information signal; the second activation signal includes a second activation signal and a second information signal; when transmitting the first activation signal, the first ECU transmits the first information signal after transmitting the first activation signal; when the first activation signal is transmitted to the bus, the second ECU transitions to an activated state while the third ECU is maintained in a sleep state; when the second ECU receives the first information signal in an activated state, it performs processing based on information included in the first information signal and transmits the second activation signal before transitioning to a sleep state; further, when transmitting the second activation signal, the second ECU transmits the second information signal after transmitting the second activation signal; when the second activation signal is transmitted to the bus, the third ECU transitions to an activated state while the first ECU is maintained in a sleep state; and when the third ECU receives the second information signal in an activated state, it performs processing based on information included in the second information signal.

[0019] In the above-described in-vehicle system, when the first ECU transmits the first activation signal, it transmits the first information signal after transmitting the first activation signal, so that the first information signal can be provided to the second ECU that has transitioned to an activated state in response to the first activation signal. With this configuration, the second ECU does not need to retain information necessary for executing a process from a stage before transitioning to an activated state. Furthermore, in the above-described in-vehicle system, when the second ECU transmits the second activation signal, it transmits the second information signal after transmitting the second activation signal, so that the second information signal can be provided to the third ECU that has transitioned to an activated state in response to the second activation signal. With this configuration, the third ECU does not need to retain information necessary for executing a process from a stage before transitioning to an activated state.

[0020] [Details of the embodiment of the present disclosure] <First embodiment> 1-1. Configuration of in-vehicle system 10 Fig. 1 shows a vehicle 1 equipped with an in-vehicle system 10. The in-vehicle system 10 includes a first ECU 11, a second ECU 12, a third ECU 13, an actuator 14, and a bus 20.

[0021] The first ECU 11, the second ECU 12, and the third ECU 13 are each an electronic control unit. The first ECU 11, the second ECU 12, and the third ECU 13 are each electrically connected to a bus 20 and can communicate with each other via the bus 20. The actuator 14 operates to open and close the door locks of the vehicle 1. The actuator 14 is controlled by the third ECU 13. The bus 20 is, for example, a communication bus such as a CAN bus.

[0022] The first ECU 11, the second ECU 12, and the third ECU 13 each transition between an active state and a sleep state. The sleep state consumes less power than the active state. The first ECU 11, the second ECU 12, and the third ECU 13 can transition only specific ECUs from the sleep state to an active state by transmitting signals via the bus 20. For example, the first ECU 11, the second ECU 12, and the third ECU 13 can transition only the ECUs designated as the active ECUs by transmitting activation signals to the bus 20, each including information indicating the ECUs to be activated. When the first ECU 11, the second ECU 12, and the third ECU 13 receive an activation signal, they determine whether the ECU designated as the active ECU is themselves. If they determine that the ECU is themselves, they transition to the active state. If they determine that the ECU is not themselves, they do not transition to the active state. The first ECU 11, the second ECU 12, and the third ECU 13 are, for example, compatible with a partial network.

[0023] As shown in FIG. 2 , the first ECU 11 includes a wireless communication unit 11A, a first communication unit 11B, a first control unit 11C, and a first storage unit 11D. The wireless communication unit 11A is, for example, an antenna outside the vehicle cabin, and performs wireless communication with a key device 90 (see FIG. 1 ). The wireless communication unit 11A receives key information transmitted from the key device 90. The key device 90 is, for example, an electronic key or a mobile terminal carried by the user. The first communication unit 11B is a communication interface for performing communication via the bus 20. The first communication unit 11B includes, for example, a transceiver compatible with the partial network standard. The first control unit 11C includes, for example, a microcomputer. The first control unit 11C performs predetermined processing according to a program stored in the first storage unit 11D.

[0024] The second ECU 12 has a second communication unit 12B, a second control unit 12C, and a second storage unit 12D. The second communication unit 12B is a communication interface for communicating via the bus 20. The second communication unit 12B includes, for example, a transceiver that complies with the partial network standard. The second control unit 12C includes, for example, a microcomputer. The second control unit 12C performs predetermined processing in accordance with a program stored in the second storage unit 12D.

[0025] The third ECU 13 has a third communication unit 13B, a third control unit 13C, and a third storage unit 13D. The third communication unit 13B is a communication interface for communicating via the bus 20. The third communication unit 13B includes, for example, a transceiver that complies with the partial network standard. The third control unit 13C includes, for example, a microcomputer. The third control unit 13C performs predetermined processing in accordance with a program stored in the third storage unit 13D.

[0026] Next, the operations of the first ECU 11, the second ECU 12, and the third ECU 13 will be described with reference to Fig. 3. At the start of the process shown in Fig. 3, the first ECU 11, the second ECU 12, and the third ECU 13 are all in a sleep state.

[0027] When the activation condition is satisfied at T11, the first ECU 11 transitions to an activated state at T12. Then, the first ECU 11 transmits a first activation signal to cause the second ECU 12 to transition to an activated state at T13 and T14, and then transitions to a sleep state at T16. After transmitting the first activation signal, the first ECU 11 immediately transitions to the sleep state.

[0028] In this embodiment, the activation condition is that the first ECU 11 receives key information transmitted from the key device 90. The key information may be, for example, an ID code. The key device 90 transmits the key information when the user performs an unlocking operation.

[0029] The first activation signal is an activation signal including information indicating that the activation target is the second ECU 12. The first activation signal includes a first activation signal and a first information signal. The first activation signal is a signal including information indicating that the activation target is the second ECU 12. The first information signal is a signal including key information. When transmitting the first activation signal, the first ECU 11 transmits the first information signal after transmitting the first activation signal. The timing of transmitting the first information signal may be after a predetermined time has elapsed since transmitting the first activation signal, may be immediately after transmitting the first activation signal, or may be at another timing.

[0030] When the first activation signal is transmitted to the bus 20 at T13, the second ECU 12 is activated at T14 while the third ECU 13 remains in a sleep state. Specifically, the first activation signal is received by both the third ECU 13 and the second ECU 12. However, the third ECU 13 determines based on the information contained in the first activation signal that it is not the activation target and remains in the sleep state. In contrast, the second ECU 12 determines based on the information contained in the first activation signal that it is the activation target and transitions to an activated state.

[0031] When the first information signal is transmitted to the bus 20 at T15, the second ECU 12 receives the first information signal. Note that the third ECU 13 is in a sleep state and does not operate even when the first information signal is transmitted. When the second ECU 12 receives the first information signal in an activated state, it performs processing based on the information contained in the first information signal. Specifically, when the second ECU 12 receives the first information signal, it determines whether authentication is successful based on the key information contained in the first information signal at T17. If the second ECU 12 determines that authentication is not successful, it transitions to a sleep state at T18 without transmitting a second activation signal. If the second ECU 12 determines that authentication is successful, it transmits second activation signals at T19 and T21 and then transitions to a sleep state at T22. After transmitting the second activation signal, the second ECU 12 immediately transitions to a sleep state.

[0032] The second activation signal is an activation signal including information indicating that the activation target is the third ECU 13. The second activation signal includes a second activation signal and a second information signal. The second activation signal is a signal including information indicating that the activation target is the third ECU 13. The second information signal is a signal including information indicating that authentication has been established. When transmitting the second activation signal, the second ECU 12 transmits the second information signal after transmitting the second activation signal. The timing for transmitting the second information signal may be after a predetermined time has elapsed since transmitting the second activation signal, or immediately after transmitting the second activation signal, or may be at another timing.

[0033] When the second activation signal is transmitted to the bus 20 at T19, the first ECU 11 remains in the sleep state, and the third ECU 13 is activated at T20. Specifically, the second activation signal is received by both the first ECU 11 and the third ECU 13. However, the first ECU 11 determines that it is not the activation target based on the information contained in the second activation signal, and remains in the sleep state. In contrast, the third ECU 13 determines that it is the activation target based on the information contained in the second activation signal, and transitions to the activated state at T20.

[0034] When the second information signal is transmitted to the bus 20 at T21, the third ECU 13 receives the second information signal. Note that the first ECU 11 is in a sleep state and does not operate even when the second information signal is transmitted. When the third ECU 13 receives the second information signal in an activated state, the third ECU 13 performs processing based on the information contained in the second information signal at T23. Specifically, when the third ECU 13 receives the second information signal, it controls the actuator 14 to unlock the door. After unlocking the door, the third ECU 13 transitions to a sleep state at T24.

[0035] As described above, the first ECU 11 of the in-vehicle system 10 transitions to an active state and transmits a first activation signal when the activation condition is met. When the first activation signal is transmitted to the bus 20, the second ECU 12 transitions to an active state while the third ECU 13 remains in a sleep state. The second ECU 12 then performs processing based on the information contained in the first activation signal. Moreover, the first ECU 11 transitions to a sleep state after transmitting the first activation signal. Therefore, the in-vehicle system 10 can easily reduce the power consumption of the first ECU 11, which can transition only the second ECU 12 to an active state and perform a predetermined operation.

[0036] In the in-vehicle system 10, the third ECU 13 can transition to an activated state in response to the second activation signal transmitted from the second ECU 12, and can perform processing based on information contained in the second activation signal. Moreover, even when the second activation signal is transmitted, the first ECU 11 does not transition to an activated state, so that power consumption due to the first ECU 11 transitioning to an activated state can be reduced.

[0037] The in-vehicle system 10 can reduce power consumption, transition the first ECU 11 to an active state in response to reception of key information, and have the second ECU 12 determine whether authentication has been successful. If it is determined that authentication has been successful, the in-vehicle system 10 can transition the third ECU 13 to an active state and transition the second ECU 12 to a sleep state.

[0038] In the in-vehicle system 10, when the first ECU 11 transmits the first activation signal, it transmits the first information signal after transmitting the first activation signal. This allows the first information signal to be provided to the second ECU 12, which has transitioned to an activated state in response to the first activation signal. With this configuration, the second ECU 12 does not need to retain information necessary for executing a process from a stage before transitioning to an activated state. Furthermore, in the in-vehicle system 10, when the second ECU 12 transmits the second activation signal, it transmits the second information signal after transmitting the second activation signal. This allows the second information signal to be provided to the third ECU 13, which has transitioned to an activated state in response to the second activation signal. With this configuration, the second ECU 12 does not need to retain information necessary for executing a process from a stage before transitioning to an activated state.

[0039] <Other Embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of features of the above-described or below-described embodiments is possible within a range that does not contradict. Furthermore, any feature of the above-described or below-described embodiments may be omitted unless explicitly stated as essential. Furthermore, the above-described embodiments may be modified as follows.

[0040] The in-vehicle system 10 may include an ECU other than the first ECU 11 , the second ECU 12 , and the third ECU 13 .

[0041] In the first embodiment, the first activation signal is composed of two signals, the first activation signal and the first information signal. However, the first activation signal may be a single signal. In this case, the first activation signal includes both the information included in the first activation signal and the information included in the first information signal.

[0042] In the first embodiment, the second activation signal is composed of two signals, the second activation signal and the second information signal. However, the second activation signal may be a single signal. In this case, the second activation signal includes both the information included in the second activation signal and the information included in the second information signal.

[0043] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0044] REFERENCE SIGNS LIST 1 vehicle 10 in-vehicle system 11 first ECU 11A wireless communication unit 11B first communication unit 11C first control unit 11D first storage unit 12 second ECU 12B second communication unit 12C second control unit 12D second storage unit 13 third ECU 13B third communication unit 13C third control unit 13D third storage unit 14 actuator 20 bus 90 key device

Claims

1. An in-vehicle system comprising a first ECU, a second ECU, and a third ECU connected to the same bus, wherein the first ECU shifts from a sleep state to an active state when a startup condition is satisfied, transmits a first startup signal to start the second ECU, and then shifts to the sleep state. When the first startup signal is transmitted to the bus, the second ECU shifts to the active state while the third ECU remains in the sleep state. When the second ECU receives the first startup signal, the second ECU performs processing based on the information included in the first startup signal.

2. When the second ECU receives the first startup signal, the second ECU performs processing based on the information included in the first startup signal, transmits a second startup signal to shift the third ECU to the active state, and then shifts to the sleep state. When the second startup signal is transmitted to the bus, the third ECU shifts to the active state while the first ECU remains in the sleep state. When the third ECU receives the second startup signal, the third ECU performs processing based on the information included in the second startup signal. The in-vehicle system according to claim 1.

3. The first ECU has a wireless communication unit that receives key information transmitted from a key device. When the first ECU receives the key information, the first ECU shifts from the sleep state to the active state, transmits the first startup signal including the key information, and then shifts to the sleep state. When the first startup signal is transmitted to the bus, the second ECU shifts to the active state while the third ECU remains in the sleep state. When the second ECU receives the first startup signal, the second ECU determines whether authentication is established based on the key information included in the first startup signal. When it is determined that authentication is established, the second ECU transmits the second startup signal and then shifts to the sleep state. The in-vehicle system according to claim 2.

4. The first activation signal includes a first activation signal and a first information signal. When the first ECU transmits the first activation signal, it transmits the first information signal after transmitting the first activation signal. When the first activation signal is transmitted to the bus, the second ECU transitions to the activated state while the third ECU remains in the sleep state. The in-vehicle system according to claim 1, wherein when the second ECU receives the first information signal in the activated state, the second ECU performs processing based on the information included in the first information signal.

5. The first activation signal includes a first activation signal and a first information signal. The second activation signal includes a second activation signal and a second information signal. When the first ECU transmits the first activation signal, it transmits the first information signal after transmitting the first activation signal. When the first activation signal is transmitted to the bus, the second ECU transitions to the activated state while the third ECU remains in the sleep state. When the second ECU receives the first information signal in the activated state, the second ECU performs processing based on the information included in the first information signal and then transitions to the sleep state after transmitting the second activation signal. Further, when the second ECU transmits the second activation signal, it transmits the second information signal after transmitting the second activation signal. When the second activation signal is transmitted to the bus, the third ECU transitions to the activated state while the first ECU remains in the sleep state. The in-vehicle system according to claim 2, wherein when the third ECU receives the second information signal in the activated state, the third ECU performs processing based on the information included in the second information signal.

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