JP5920038B2 - In-vehicle communication device - Google Patents

Description

  The present invention relates to an in-vehicle communication device that is mounted on a vehicle and communicates with other communication devices in the vehicle via an in-vehicle network of the vehicle.

  A technique is known in which a plurality of in-vehicle communication devices in a vehicle are connected by an in-vehicle network using a protocol such as CAN (Controller Area Network), and data communication is performed with each other. Further, it is known that such an in-vehicle communication device has an operation state that is changed between a wake-up state in which a communication function can be used and a sleep state in which the communication function is stopped for power saving.

  For example, Patent Document 1 discloses that when the ECU as the in-vehicle communication device detects that a predetermined sleep condition is established, the ECU shifts to a sleep state in which control processing, communication processing, and the like are stopped. . When the wakeup signal detection unit of the transceiver that mediates the exchange of signals between the microcomputer with the built-in communication controller and the vehicle-mounted LAN detects a wakeup signal sent from another ECU, it shifts from the sleep state to the wakeup state. Is disclosed.

  In recent years, the number of ECUs on a single in-vehicle network (that is, the above-described in-vehicle communication device) has increased, and the number of ECUs to which one ECU performs data communication on a single in-vehicle network. Has been increasing.

JP 2008-263346 A

  In the technique disclosed in Patent Document 1, in order to detect the wakeup signal sent from another ECU by the wakeup signal detection unit of the transceiver, at least the wakeup signal detection unit is operated even in the sleep state. It was necessary to supply power to the transceiver.

  Further, as described above, when the number of ECUs to which one ECU performs data communication on a single in-vehicle network increases, it is considered that the communication speed decreases due to the crowded network. As one proposal for solving this problem, an ECU to which data communication is performed by one ECU is assigned to a plurality of in-vehicle networks, and a plurality of in-vehicle networks are assigned to each of the plurality of in-vehicle networks. It is conceivable to provide a transceiver. In this case, it is conceivable to change the operating state between the wake-up state and the sleep state for each of the plurality of transceivers.

  Here, when adopting a configuration including a plurality of transceivers in one ECU, if the technique disclosed in Patent Document 1 is applied, a wake-up signal detection unit is provided for each of the plurality of transceivers. In this case, even when the transceiver is in the sleep state, it is necessary to supply each of the plurality of transceivers with power to operate at least the wakeup signal detection unit, and thus the dark current in the sleep state increases. The problem arises.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an in-vehicle communication device capable of suppressing an increase in dark current in a sleep state even when a plurality of transceivers are provided. There is.

First invention according to the vehicle mounting the communication apparatus, while being mounted on a vehicle, a vehicle-mounted communication apparatus for performing another communication device and the data communication is a communication apparatus other than the own device via the vehicle network (1), Multiple transceivers (11a, 11b, and 11c) that transmit and receive data signals to and from other communication devices (2a, 2b, and 2c) on different in-vehicle networks, and power supply and power supply cutoff for each transceiver of the multiple transceivers A plurality of switches (12a, 12b, and 12c) that can be switched individually, a power supply management unit (14) that controls the plurality of switches, and a necessity determination that determines whether power supply to each transceiver is necessary parts (15), the signals transmitted to each transceiver from the other communication devices on different vehicle network respectively, about which transceivers One monitoring unit for detecting the signal or differentiate to (16), the separately provided from each transceiver, power supply management unit, among the transceiver, the transceiver only the power supply by necessity determining unit determines that unnecessary By controlling the switch to cut off the power supply, the transceiver was shifted from a wake-up state in which data signals were transmitted / received to a sleep state in which data signals were not transmitted / received , and the power supply was cut off. Of the transceivers, the switch is controlled so that power is supplied only to the transceiver whose signal is detected by the monitoring unit .
A second invention related to the in-vehicle communication device is an in-vehicle communication device (1) that is mounted on a vehicle and performs data communication with another communication device that is a communication device other than the own device via an in-vehicle network, A plurality of transceivers (11a, 11b, and 11c) that transmit and receive data signals to and from other communication devices (2a, 2b, and 2c) on different in-vehicle networks; and power supply and power supply cutoff for each transceiver of the plurality of transceivers Switches (12a, 12b, 12c) that can be switched individually, a power supply management unit (14) that controls the plurality of switches, and a necessity determination unit that determines whether power supply to each transceiver is necessary (15), and the power supply management unit supplies power only to the transceivers determined by the necessity determination unit that power supply is unnecessary among the transceivers. By controlling the switch to cut off the supply, the transceiver is shifted from a wake-up state in which data signals are transmitted / received to a sleep state in which data signals are not transmitted / received. It is characterized in that a certain vehicle state is detected and whether or not it is necessary to supply power to each transceiver is determined based on the detected vehicle state.
A third invention relating to an in-vehicle communication device is an in-vehicle communication device (1) that is mounted on a vehicle and performs data communication with another communication device that is a communication device other than the own device via an in-vehicle network, A plurality of transceivers (11a, 11b, and 11c) that transmit and receive data signals to and from other communication devices (2a, 2b, and 2c) on different in-vehicle networks; and power supply and power supply cutoff for each transceiver of the plurality of transceivers Switches (12a, 12b, 12c) that can be switched individually, a power supply management unit (14) that controls the plurality of switches, and a necessity determination unit that determines whether power supply to each transceiver is necessary (15), and the power supply management unit supplies power only to the transceivers determined by the necessity determination unit that power supply is unnecessary among the transceivers. By controlling the switch to cut off the power supply, the transceiver is shifted from the wake-up state in which the data signal is transmitted / received to the sleep state in which the data signal is not transmitted / received. The necessity of power supply to each transceiver is determined based on the presence / absence of a signal that allows the transceiver to enter the sleep state or the presence / absence of a signal that requests the transceiver to enter the sleep state. It is characterized by that.

  According to this, for the transceiver that the necessity determination unit determines that the power supply is unnecessary, the power supply management unit controls the switch so that the power supply is cut off, and the power supply is cut off, and the sleep state is entered. Therefore, power consumption can be reduced to 0 in the sleep state.

  In addition, switching between power supply and power supply cutoff is performed according to an instruction from the power supply management unit. However, since the power supply management unit instructs the switching for each transceiver of a plurality of transceivers, a plurality of power supply management units are provided. It is not necessary to have the same number of transceivers. In the sleep state, each transceiver can be shifted to the wake-up state by the power supply management unit. Therefore, the sleeper is in a sleep state as compared with the configuration in which the same number of members for switching from the power supply cutoff to the power supply are provided. The dark current in the state can be suppressed. As a result, even when a plurality of transceivers are provided, an increase in dark current in the sleep state can be suppressed.

1 is a block diagram showing a schematic configuration of an in-vehicle communication system 100. FIG. 2 is a block diagram showing a schematic configuration of an ECU 1. FIG. It is a flowchart which shows an example of the flow of the operation state change related process in ECU1. It is a block diagram which shows the schematic structure of ECU1a. It is a flowchart which shows an example of the flow of the operation state change related process in ECU1a.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The in-vehicle communication system 100 shown in FIG. 1 is mounted on a vehicle, and is connected to the ECU 1 and the bus line 3a connected to the bus lines 3a, 3b, and 3c of different in-vehicle networks (hereinafter referred to as in-vehicle LANs). ECU 2a connected to bus line 3b, and ECU 2c connected to bus line 3c. The ECU 1 corresponds to the in-vehicle communication device in the claims, and the ECUs 2a, 2b, and 2c correspond to the other communication devices in the claims.

  The different in-vehicle LANs referred to here may be in-vehicle LANs having different communication protocols such as CAN (controller area network), LIN (Local Interconnect Network), and FlexRay (registered trademark). It may be an in-vehicle LAN such as a sub-network that is the same but the bus lines are not directly connected to each other. In the present embodiment, as an example, the following description will be given assuming that different in-vehicle LANs are all in-vehicle LANs compliant with CAN.

  In the present embodiment, the case where the bus lines to which the ECU 1 is connected is three bus lines 3a, 3b, and 3c will be described as an example, but the present invention is not necessarily limited thereto. For example, the number may be two or more than three. In the present embodiment, it is assumed that a bus line made up of a set of two wires is counted as one.

  In the present embodiment, for convenience, only one ECU other than the ECU 1 connected to the bus lines 3a, 3b, and 3c is shown. However, the number of ECUs other than the ECU 1 connected to each bus line is two. There shall be at least two.

  Subsequently, the ECU 1 will be described in detail with reference to FIG. As shown in FIG. 2, the ECU 1 includes a CAN transceiver 11 a, a CAN transceiver 11 b, a CAN transceiver 11 c, a switch unit 12, a transceiver power supply 13, a power supply management unit 14, and an MPU (Micro-Processing Unit) 15.

  The CAN transceiver 11a exchanges data signals with the ECU 2a on the bus line 3a, the CAN transceiver 11b exchanges data signals with the ECU 2b on the bus line 3b, and the CAN transceiver 11c communicates with the ECU 2c on the bus line 3c. Send and receive data signals. Therefore, the CAN transceivers 11a, 11b, and 11c correspond to the transceivers in the claims. In FIG. 2, Tx indicates transmission and Rx indicates reception.

  In the present embodiment, a configuration in which the ECU 1 includes the three transceivers of the CAN transceivers 11a, 11b, and 11c is shown, but the present invention is not necessarily limited thereto. The number of transceivers provided in the ECU 1 may be plural, and is determined according to the number of bus lines to which the ECU 1 is connected.

  The switch unit 12 includes switch elements 12a, 12b, and 12c that can individually switch between power supply to the CAN transceivers 11a, 11b, and 11c and interruption of power supply. Therefore, the switch elements 12a, 12b, and 12c correspond to the switches in the claims.

  When the switch element 12a is on, the transceiver power supply 13 and the CAN transceiver 11a are electrically connected to supply power to the CAN transceiver 11a. On the other hand, when the switch element 12a is off, the transceiver power supply 13 and the CAN transceiver 11a are not electrically connected, and the power supply from the transceiver power supply 13 to the CAN transceiver 11a is cut off.

  Similarly, the switch element 12b switches between power supply to the CAN transceiver 11b and interruption of power supply, and the switch element 12c switches between power supply to the CAN transceiver 11c and interruption of power supply.

  The power supply management unit 14 controls on / off switching of the switch elements 12a, 12b, and 12c. The MPU 15 has a well-known configuration including a CPU, ROM, RAM, and the like (not shown), and performs arithmetic processing according to a program stored in a memory such as a ROM based on signals input from the CAN transceivers 11a, 11b, 11c, and the like. Run.

  In the present embodiment, it is assumed that the MPU 15 has an IG monitor terminal that monitors the voltage of the IG terminal to which the voltage from the ignition switch of the vehicle is applied and an ACC monitor terminal that monitors the voltage from the accessory switch of the vehicle. Further, the MPU 15 determines whether the ignition (IG) power supply of the vehicle or the accessory (ACC) power supply is turned on or off according to the voltage monitored by the IG monitor terminal or the ACC monitor terminal. Then, an arithmetic process described in detail later is executed according to whether the IG power supply is turned on or off or the ACC power supply is turned on or off.

  Although not shown, it is assumed that the power supply management unit 14 and the MPU 15 are supplied with power from a power supply circuit. For the switch elements 12a, 12b, and 12c, for example, a configuration that can be switched on and off under the control of the power supply management unit 14 may be adopted even if power is not supplied.

  Returning to FIG. 1, the ECUs 2 a, 2 b, and 2 c are mainly configured as microcomputers, and each includes a known CPU, ROM, RAM, I / O, and a bus connecting them. The ECUs 2a, 2b, and 2c may be the same ECUs as the ECU 1, but in the present embodiment, the following description will be made assuming that the ECUs are known ECUs having only one transceiver.

  Next, with reference to the flowchart of FIG. 3, processing related to a change in the operating state between the sleep state and the wake-up state for each of the CAN transceivers 11a, 11b, and 11c in the ECU 1 (hereinafter referred to as an operating state change related process) will be described. I do.

  Note that the wake-up state for each of the CAN transceivers 11a, 11b, and 11c mentioned here indicates a state in which power is supplied from the transceiver power supply 13 and data signals can be transmitted and received. The sleep state indicates a state in which power supply from the transceiver power supply 13 is interrupted and data signals cannot be transmitted / received.

  The flow in FIG. 3 may be configured to start when power supply to the power supply management unit 14 and the MPU 15 is started, for example. In the following description, the switch elements 12a, 12b, and 12c are assumed to be on in the default state.

  First, in step S1, the MPU 15 determines whether or not a condition for shifting the transceiver to the sleep state (hereinafter referred to as a sleep condition) is satisfied. The sleep condition includes, for example, detection of IG power supply OFF, detection of ACC power supply OFF, input of a sleep request from the transceiver, input of sleep permission from the transceiver, and the like.

  The sleep request from the transceiver is a signal for requesting transition to the sleep state output from the transceiver itself. In addition, the sleep permission from the transceiver refers to a case where the transceiver makes an inquiry to the ECU that is the object of data communication whether the transition to the sleep state may be performed, and permission is obtained from all of the ECUs. The signal to be output to

  In step S1, if it is determined that the sleep condition is satisfied (YES in step S1), the process proceeds to step S2. On the other hand, if it is determined that the sleep condition is not satisfied (NO in step S1), the flow of step S1 is repeated.

  In step S2, the MPU 15 performs a sleep target selection process, and proceeds to step S3. In the sleep target selection process, it is determined whether or not it is necessary to supply power to the CAN transceivers 11a, 11b, and 11c according to the established sleep condition. In other words, the transceiver to be shifted to the sleep state is selected. Therefore, the MPU 15 corresponds to a necessity determination unit in claims.

  For example, if the established sleep condition is a sleep request input or sleep permission input, it is determined that it is not necessary to supply power to the transceiver from which the sleep request or sleep permission is input. As an example, when a sleep request is input from the CAN transceiver 11a, it may be determined that power supply to the CAN transceiver 11a is unnecessary.

  Further, when the established sleep condition is detection of IG power supply off or ACC power supply off, to the type of transceiver set in advance in association with each of the IG power supply and ACC power supply on / off states. It is determined that no power supply is required. In this case, a table or map indicating correspondence between the on / off states of the IG power supply and the ACC power supply and the transceiver that cuts off the power supply of each of the CAN transceivers 11a, 11b, and 11c is stored in a nonvolatile memory such as a ROM of the MPU 15. The above configuration may be realized by storing the above in advance.

  As an example, the vehicle state of IG power off and ACC power on is associated with the need for no power supply to the CAN transceiver 11a, or the vehicle state of ACC power off is the power to the CAN transceivers 11a and 11c. What is necessary is just to make it the structure which matches supply with unnecessary.

  In step S3, the power supply management unit 14 performs a power supply cutoff process, and proceeds to step S4. In the power supply cut-off process, the power supply management unit 14 performs control to turn off the switch element corresponding to the transceiver that is determined not to require power supply in the sleep target selection process described above, and proceeds to step S4. For example, if the sleep target selection process determines that power supply to the CAN transceivers 11a and 11c is unnecessary, control is performed to turn off the switch elements 12a and 12c.

  The transceiver in which the corresponding switch element is turned off enters a sleep state in which power supply from the transceiver power supply 13 is cut off and data signals cannot be transmitted and received. On the other hand, the transceiver in which the corresponding switch element remains on is continuously supplied with power from the transceiver power supply 13 and maintains a wake-up state in which data signals can be transmitted and received.

  In step S4, the MPU 15 determines whether or not a condition for shifting the transceiver to the wake-up state (hereinafter referred to as a wake-up condition) is satisfied. Examples of the wake-up condition include detection of switching from off to on of the IG power supply, detection of off from the ACC power supply to on, and the like.

  If it is determined in step S4 that the wake-up condition is satisfied (YES in step S4), the process proceeds to step S5. On the other hand, if it is determined that the wake-up condition is not satisfied (NO in step S4), the process proceeds to step S7.

  In step S5, the MPU 15 performs a wake-up target selection process, and proceeds to step S6. In the wake-up target selection process, it is determined whether or not it is necessary to supply power to each of the CAN transceivers 11a, 11b, and 11c according to the established wake-up condition. In other words, the transceiver that should be in the wake-up state is selected.

  As a specific example, it is determined that it is necessary to supply power to a transceiver other than the type of transceiver set in advance in association with each of the on / off states of the IG power supply and the ACC power supply. In this case, as described above, the non-volatile memory such as the ROM of the MPU 15 is connected to the on / off state of the IG power supply and the ACC power supply and the transceiver that cuts off the power supply of each of the CAN transceivers 11a, 11b, and 11c. The above configuration may be realized by storing a table, a map, or the like indicating the correspondence relationship in advance.

  In step S6, the power supply management unit 14 performs a power supply return process. In the power supply recovery process, the power supply management unit 14 performs control to turn on the switch element corresponding to the transceiver that is determined to require power supply in the wake-up target selection process described above, and proceeds to step S7. For example, when the wake-up target selection process determines that power supply to the CAN transceivers 11b and 11c is necessary, control is performed to turn on the switch elements 12b and 12c. Note that a switch element that is already on may be configured to maintain the on state.

  Among the transceivers that are in the sleep state, the transceiver in which the corresponding switch element is turned on resumes the power supply from the transceiver power supply 13 and returns to the wake-up state where data signals can be transmitted and received. On the other hand, in the transceiver in which the corresponding switch element remains off, power supply from the transceiver power supply 13 is continuously cut off, and a sleep state in which data signals cannot be transmitted and received is maintained.

  In step S7, if all of the CAN transceivers 11a, 11b, and 11c are in the sleep state (YES in step S7), the process returns to step S4 and the flow is repeated. On the other hand, if any of the CAN transceivers 11a, 11b, and 11c is in a wake-up state (NO in step S7), the process returns to step S1 to repeat the flow.

  According to the above configuration, since the CAN transceivers 11a, 11b, and 11c are shifted to the sleep state by cutting off the power supply from the transceiver power supply 13, the power consumption in the transceiver that has shifted to the sleep state can be reduced to zero. .

  Further, only one power supply management unit 14 for controlling the switch unit 12 to switch the power supply and the power supply cutoff of the CAN transceivers 11a, 11b, and 11c is provided for a plurality of transceivers. ing. Even when the CAN transceivers 11a, 11b, and 11c are shifted to the sleep state, the single power supply management unit 14 can shift the CAN transceivers 11a, 11b, and 11c to the wake-up state. Therefore, according to the configuration of the first embodiment, the dark current in the sleep state is reduced compared to the configuration in which the same number of members for switching from the power supply cutoff to the power supply in the sleep state as the CAN transceivers 11a, 11b, and 11c are provided. Can be suppressed. As a result, even when a plurality of transceivers are provided, an increase in dark current in the sleep state can be suppressed.

  In the first embodiment, both the on / off state of the IG power supply and the on / off state of the ACC power supply have been described as being used for the conditions for shifting the transceiver to the sleep state or the wakeup state. However, the present invention is not limited to this. For example, only one of the on / off state of the IG power supply and the on / off state of the ACC power supply may be used as a condition for shifting the transceiver to the sleep state or the wakeup state.

  In the first embodiment, the configuration in which the MPU 15 performs the processing of Step S1 to Step S2 and Step S4 to Step S5 is shown, but the configuration is not necessarily limited thereto. For example, the process of steps S1 to S2 and steps S4 to S5 may be performed by a simple circuit other than a microcomputer.

(Embodiment 2)
The present invention is not limited to the above-described first embodiment, and the following second embodiment is also included in the technical scope of the present invention. Below, this Embodiment 2 is demonstrated using FIG.4 and FIG.5. For convenience of explanation, members having the same functions as those shown in the drawings used in the description of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The in-vehicle communication system 100 according to the second embodiment has the same configuration as the in-vehicle communication system 10 according to the first embodiment, except that the ECU 1a is included instead of the ECU 1. The ECU 1a has the same configuration as that of the ECU 1 of the first embodiment except that the wake-up monitoring unit 16 is provided and that the processing in steps S4 to S6 in the above-described operation state change related processing is different.

  The wake-up monitoring unit 16 is a circuit for monitoring a wake-up signal (interrupt signal) input from the bus lines 3a, 3b, and 3c to the ECU 1a. The wake-up monitoring unit 16 distinguishes signals transmitted from the ECUs 2a, 2b, and 2c on the bus lines 3a, 3b, and 3c to the ECU 1a (specifically, the CAN transceivers 11a, 11b, and 11c) from which transceiver. Detect. The wakeup monitoring unit 16 corresponds to the monitoring unit in the claims.

  As an example, the wakeup monitoring unit 16 performs a reception interrupt on a signal input to each of the CAN transceivers 11a, 11b, and 11c in the sleep state from each of the bus lines 3a, 3b, and 3c, and responds to the bus line that has received the signal. A circuit for setting the flag may be used.

  The wakeup monitoring unit 16 samples the intensity of the received signal, determines that the wakeup signal is detected when the sampling result matches the characteristics of the predetermined wakeup signal, and outputs the wakeup signal. A flag may be set according to the received bus line. According to this, it can be detected with higher accuracy that the wake-up signal has been received.

  The power supply management unit 14 performs control to turn on the switch element depending on which bus line is set in the wakeup monitoring unit 16. For example, when the flag for the bus line 3a is set, it can be estimated that an interrupt signal has been input from the bus line 3a to the CAN transceiver 11a. Therefore, in order to resume power supply to the CAN transceiver 11a, the switch Control is performed to turn on the element 12a. Similarly, when the flags for the bus line 3b and the bus line 3c are set, the switch element 12b and the switch element 12c are controlled to turn on, respectively.

  Next, the operation state change-related processing in the ECU 1a will be described using the flowchart of FIG. Note that description of the same processing as that in the flowchart of FIG. 3 is omitted.

  First, in steps S1 to S2, the same processing as described above is performed. In step S3, a power supply cutoff process is performed in the same manner as described above, and the process proceeds to step S4a. In step S4a, when the wakeup monitoring unit 16 detects a signal (YES in step S4a), the process proceeds to step S5a. On the other hand, if the wakeup monitoring unit 16 does not detect a signal (NO in step S4a), the process proceeds to step S7.

  In step S5a, the wakeup monitoring unit 16 performs signal detection processing, and proceeds to step S6a. In the signal detection process, the wakeup monitoring unit 16 sets a flag corresponding to the bus line that has received the signal.

  In step S6a, the power supply management unit 14 performs a power supply return process. In the power supply recovery process, the power supply management unit 14 performs control to turn on the switch element corresponding to the transceiver for the bus line for which the flag has been set in the wakeup monitoring unit 16, and proceeds to step S7. For example, when the flag for the bus line 3b is set, control is performed to turn on the switch element 12b corresponding to the CAN transceiver 11b.

  In step S7, if all of the CAN transceivers 11a, 11b, and 11c are in the sleep state (YES in step S7), the process returns to step S4a and the flow is repeated. On the other hand, if any of the CAN transceivers 11a, 11b, and 11c is in a wake-up state (NO in step S7), the process returns to step S1 to repeat the flow.

  In the first embodiment, the transceiver is returned from the sleep state to the wake-up state in accordance with the on / off state of the IG power supply and the ACC power supply. A configuration is adopted in which the transceiver is returned from the sleep state to the wake-up state depending on whether a signal from the bus line is detected. Even when such a configuration is adopted, when a plurality of transceivers are provided, it is possible to obtain the same effect that an increase in dark current in the sleep state can be suppressed.

  Furthermore, according to the configuration of the second embodiment, only the transceiver that detects the signal from the corresponding bus line, that is, the transceiver that is estimated to have received the wake-up signal can be returned from the sleep state to the wake-up state. It becomes possible. Therefore, it is possible to selectively return only the transceiver actually required for data communication from the plurality of transceivers to the wake-up state.

  If the wakeup monitoring unit 16 determines that the wakeup signal has been detected and sets a flag corresponding to the bus line that has received the wakeup signal, the transceiver to which the wakeup signal has been input Only from the sleep state to the wake-up state. Therefore, it is possible to accurately return only the transceiver actually required for data communication from the plurality of transceivers to the wake-up state.

  The wake-up monitoring unit 16 may be configured to constantly monitor signals input to the ECU 1a from the bus lines 3a, 3b, and 3c, or may be configured to periodically start and perform the monitoring.

  In the second embodiment, both the on / off state of the IG power supply and the on / off state of the ACC power supply have been described as being used for the condition for transitioning to the sleep state of the transceiver. For example, only one of the on / off state of the IG power supply and the on / off state of the ACC power supply may be used as a condition for shifting the transceiver to the sleep state.

  In the second embodiment, the configuration in which the MPU 15 performs the processing in steps S1 to S2 is shown, but the present invention is not necessarily limited thereto. For example, the process of steps S1 to S2 may be performed by a simple circuit other than a microcomputer.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ECU (vehicle-mounted communication apparatus), 2a * 2b * 2c ECU (other communication apparatus), 11a * 11b * 11c CAN transceiver (transceiver), 12a * 12b * 12c Switch element (switch), 14 Power supply management part, 15 MPU (Necessity determination part)

Claims (5)

An in-vehicle communication device (1) that is mounted on a vehicle and that performs data communication with another communication device that is a communication device other than its own device via an in-vehicle network,
A plurality of transceivers (11a, 11b, 11c) that transmit and receive data signals to and from the other communication devices (2a, 2b, 2c) on the different in-vehicle networks,
A plurality of switches (12a, 12b, 12c) capable of individually switching between power supply and power supply interruption for each of the plurality of transceivers;
A power supply management unit (14) for controlling the plurality of switches;
A necessity determination unit (15) for determining whether power supply to each transceiver is necessary ;
Separately from each transceiver, one monitoring unit (16) that detects a signal transmitted from the other communication device on the different in-vehicle network to each transceiver by distinguishing the signal for which transceiver is detected. In preparation for
The power supply management unit controls the switch so as to cut off the power supply only for the transceiver that is determined as needless power supply by the necessity determination unit among the transceivers. A transition is made from a wake-up state where data signals are transmitted / received to a sleep state where data signals are not transmitted / received, and among the transceivers whose power supply is cut off, only the transceivers whose signals are detected by the monitoring unit are supplied with power. An in-vehicle communication device that controls the switch so as to perform supply . An in-vehicle communication device (1) that is mounted on a vehicle and that performs data communication with another communication device that is a communication device other than its own device via an in-vehicle network,
A plurality of transceivers (11a, 11b, 11c) that transmit and receive data signals to and from the other communication devices (2a, 2b, 2c) on the different in-vehicle networks,
A plurality of switches (12a, 12b, 12c) capable of individually switching between power supply and power supply interruption for each of the plurality of transceivers;
A power supply management unit (14) for controlling the plurality of switches;
A necessity determining unit (15) for determining whether power supply to each transceiver is necessary,
The power supply management unit controls the switch so as to cut off the power supply only for the transceiver that is determined as needless power supply by the necessity determination unit among the transceivers. Transition from a wake-up state in which data signals are transmitted and received to a sleep state in which data signals are not transmitted and received ,
The necessity determining unit detects the vehicle state is a state of the vehicle, based on the detected vehicle state, vehicle communication device characterized that you determine the necessity of the power supply of the each transceiver . In claim 2 ,
The necessity determination unit has a preset correspondence relationship between the vehicle state and the transceiver that cuts off power supply among the transceivers, and includes the detected vehicle state and the preset correspondence relationship. And determining whether or not it is necessary to supply power to each of the transceivers. In claim 2 or 3 ,
The necessity determination unit detects an on / off state of an ignition power source and an accessory power source of the vehicle as a vehicle state. An in-vehicle communication device (1) that is mounted on a vehicle and that performs data communication with another communication device that is a communication device other than its own device via an in-vehicle network,
A plurality of transceivers (11a, 11b, 11c) that transmit and receive data signals to and from the other communication devices (2a, 2b, 2c) on the different in-vehicle networks,
A plurality of switches (12a, 12b, 12c) capable of individually switching between power supply and power supply interruption for each of the plurality of transceivers;
A power supply management unit (14) for controlling the plurality of switches;
A necessity determining unit (15) for determining whether power supply to each transceiver is necessary,
The power supply management unit controls the switch so as to cut off the power supply only for the transceiver that is determined as needless power supply by the necessity determination unit among the transceivers. Transition from a wake-up state in which data signals are transmitted and received to a sleep state in which data signals are not transmitted and received ,
The necessity determination unit determines whether or not there is a signal that permits the transceiver to enter the sleep state from the other communication device, or whether or not there is a signal that requests the transceiver to enter the sleep state. based on in-vehicle communication device according to claim that you determine the necessity of the power supply of the to each transceiver.

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