Vehicle communication system

Abstract

To suppress wasteful power consumption without excessively increasing the processing capacity of a gateway device even in a case where such a situation that a wake-up request is continuously transmitted from an ECU occurs in a vehicle communication system having a sleep and wake-up function.SOLUTION: There is provided a vehicle communication system having a gateway device which relays communication between a plurality of communication lines connected with various ECUs. The gateway device has a sleep and wake-up function which transmits a wake-up request signal that shifts the target ECU from the sleep state to the wake-up state by signal reception from the communication lines. When it is determined that transmission of the wake-up request signal cannot be permitted to the power consumption of a battery, the gateway device does not transmit the wake-up request signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle communication system.

Background Art

[0002] A vehicle communication system is connected such that a plurality of electronic control units (hereinafter, ECU: Electronic Control Unit) can communicate with each other via an in-vehicle network using a communication protocol such as CAN (Controller Area Network). In addition, the in-vehicle network generally includes a gateway device (for example, CGW: Central Gateway ECU) having a relay function, and information communication between a plurality of ECUs is performed between different communication lines (communication buses) connected to the gateway device.

[0003] Further, a vehicle communication system having a sleep / wake-up function is known in order to suppress wasteful power consumption when the vehicle is not in use. In a system having this function, when a wake-up request is transmitted from a specific ECU to the communication line, the gateway device wakes up itself and then dispersedly transmits a wake-up request signal to the target ECU. As a result, the target ECU transitions from a sleep state in which power consumption is reduced to a normal state (wake-up state) in which communication can be executed.

[0004] Conventionally, in such a system, when the gateway device receives a wake-up request, it saves the data of the wake-up request in the storage unit, then enters the wake-up state, reads the data from the storage unit, and transmits it to the MPU of the gateway device. The MPU analyzes the received data to determine whether the data is appropriate (see Patent Document 1 below).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] According to the conventional technology described above, the gateway device, based on data analysis and judgment of appropriateness, distributes and transmits the wake-up request from the ECU to all other relevant ECUs if it determines that the received wake-up request is appropriate. The ECU that receives the wake-up request signal then transitions from sleep state to wake-up state.

[0007] In this case, even if the data analysis reveals that the wake-up request data itself is correct, the status of the in-vehicle equipment and the operator's operation of the control devices may cause a situation where a specific ECU continues to send wake-up requests for an extended period of time. If this situation occurs when the vehicle is not in use and the battery is not being charged, it will lead to significant battery drain and may impair the vehicle's ability to start afterward.

[0008] Furthermore, in the conventional technology described above, the gateway device analyzes the data it receives to determine whether a wake-up request is valid. However, performing such data analysis requires high processing power from the gateway device, which inevitably leads to increased system costs.

[0009] The present invention aims to address these problems. Specifically, in a vehicle communication system having a sleep / wake function, even if a situation arises where wake-up requests continue to be sent from the ECU, the present invention aims to suppress unnecessary power consumption without excessively increasing the processing capacity of the gateway device. [Means for solving the problem]

[0010] To solve these problems, the present invention has the following configuration. A vehicle communication system comprising a gateway device that relays communication between multiple communication lines to which various ECUs are connected, wherein the gateway device has a sleep-wake function that transmits a wake-up request signal to transition the target ECU from a sleep state to a wake-up state upon receiving a signal from the communication line, and is characterized in that it does not transmit the wake-up request signal if it determines that transmitting the wake-up request signal is unacceptable in terms of battery power consumption. [Effects of the Invention]

[0011] According to the present invention, which has these features, even if a situation arises in a vehicle communication system having a sleep / wake function where a wake-up request signal is continuously transmitted from one ECU, it is possible to suppress unnecessary power consumption without excessively increasing the processing capacity of the gateway device. [Brief explanation of the drawing]

[0012] [Figure 1] Diagram illustrating a vehicle communication system. [Figure 2] An explanatory diagram showing the hardware configuration of a vehicle communication system. [Figure 3] An explanatory diagram showing the operation of the wake-up request relay unit. [Figure 4] An explanatory diagram showing the processing flow of the wake-up request relay section. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals in different figures indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate.

[0014] As shown in Figure 1, the vehicle communication system 1 mounted on the vehicle 100 includes various ECUs 2 that are connected to each other in a communicative manner via multiple communication lines L (L1 to L3). Here, the communication lines L are, for example, a CAN communication bus (CAN bus), but are not limited to this and may be communication lines of other types.

[0015] Furthermore, the vehicle communication system 1 includes a gateway device (e.g., CGW: Central Gateway ECU) 3 that has a relay function for multiple communication lines L. Multiple communication lines L are connected to the gateway device 3, and ECUs 2 connected to different communication lines L can communicate with each other via the gateway device 3.

[0016] Different communication lines L (L1 to L3) connected to the gateway device 3 each establish a local area network (LAN) with a different communication system. Each LAN is, for example, a driving control system LAN that performs control to stabilize the vehicle's behavior, engine control, or air conditioning control; a body system LAN that controls door locks, seat operation, or power windows; or a multimedia system LAN that controls audio equipment and navigation systems. One or more ECUs 2 that function for each of these communication systems are connected to each communication line L.

[0017] Furthermore, the vehicle communication system 1 is powered by the battery 4 of the vehicle 100, and the aforementioned ECU 2 and gateway device 3 are connected to the battery 4 via a power supply line H.

[0018] As shown in FIG. 2, each ECU 2 is composed of a microcontroller 20 including, as hardware, a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, an external I / F (Interface) 24, and a communication circuit 25. The communication circuit 25 of the microcontroller 20 is connected to the communication line L via a communication transceiver 26.

[0019] The CPU 21 performs various controls in each of the aforementioned LANs by executing various programs stored in the ROM 22. The ROM 22 is a non-volatile memory. For example, the ROM 22 stores programs executed by the CPU 21, data necessary for the CPU 21 to execute programs, and the like. The RAM 23 is a main memory device such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory). For example, the RAM 23 functions as a work area used when the CPU 21 executes programs. The external I / F 24 controls the transmission and reception of data to and from the outside, and various in-vehicle devices 5 are connected to the ECU 2 via the external I / F 24.

[0020] Similar to the ECU 2, the gateway device 3 is composed of a microcontroller 30 including a CPU 31, a ROM 32, a RAM 33, an external I / F 34, and a communication circuit 35. The gateway device 3 has a plurality of communication circuits 35 in the microcontroller 30, and communication lines L (L1 to L5) are connected to each communication circuit 35 via a communication transceiver 36.

[0021] The vehicle communication system 1 has a sleep-wakeup function that suppresses the power supplied from the battery 4 to the ECU 2 and the gateway device 3 when the vehicle 100 is not in use in order to suppress the depletion of the battery 4. Also, in order to execute this sleep-wakeup function, the CPU 21 of the ECU 2 is equipped with a wakeup request transmitter 21W as a software configuration, and the CPU 31 of the gateway device 3 is equipped with a wakeup request relay unit 31W as a software configuration.

[0022] The wakeup request transmitter 21W provided in each ECU 2 transmits a wakeup request signal W1 in response to a signal from the in-vehicle device 5 connected to the ECU 2. When the ECU 2 transmits the wakeup request signal W1, as shown in FIG. 3, the wakeup request signal W1 is transmitted to the gateway device 3 (GW) via the communication line L (for example, the communication line L1).

[0023] Then, basically, when the wakeup request relay unit 31W provided in the gateway device 3 receives the wakeup request signal W1, it identifies the communication line L of the ECU 2 targeted by the wakeup request signal W1 (or for all communication lines L), and as shown in FIG. 3, performs a relay operation of transmitting the wakeup request signal W1 to the identified communication line L (for example, the communication line L2).

[0024] Also, the gateway device 3 wakes itself up by receiving not only the wakeup request signal W1 transmitted from the ECU 2 but also all signals sent from the communication line L (for example, all CAN signals), and transmits the wakeup request signal W1 to the target ECU 2.

[0025] Then, as an example, the gateway device 3 executes the processing flow shown in FIG. 4, and when it determines that it meets a specific condition, it executes a process of not transmitting the wakeup request signal W1 (for example, blocking the relay of the wakeup request).

[0026] The following explanation will use the case where a wake-up request signal W1 sent from one ECU2 is relayed to another ECU2 in the gateway device 3 as an example.

[0027] As shown in Figure 4, the wake-up request relay unit 31W remains in a standby state until it receives a wake-up request signal W1 (step S1: NO). Upon receiving the wake-up request signal W1 (step S1: YES), it executes a series of processes S2. If this process S2 determines that the continuation of the wake-up request signal W1 is unacceptable in terms of the power consumption of the battery 4, it blocks the relay between the communication line L (e.g., communication line L1) on which the continuing wake-up request signal W1 is being transmitted and another communication line L (e.g., communication line L2), thereby preventing the transmission of the wake-up request signal W1 (step S3).

[0028] Let's explain a more specific example of the series of processes S2. When the gateway device 3 receives the wake-up request signal W1 (step S1: YES), in step S21, it identifies the ECU2 that transmitted the received wake-up request signal W1 and determines whether or not it is a pre-configured ECU2 (step S21). If the wake-up request signal W1 was transmitted from a pre-configured ECU2 (step S21: YES), it relays the wake-up request signal W1 as a normal process (step S4).

[0029] The pre-configured ECU2 here is, in a sense, an ECU2 that is expected to start the vehicle 100 after the wake-up request signal W1 is sent. Examples of such ECU2s include one that sends a wake-up request signal W1 in response to input from the vehicle start switch (e.g., the ignition switch), one that sends a wake-up request signal W1 when the driver's side door is opened, and one that sends a wake-up request signal W1 when it detects a person sitting in the driver's seat.

[0030] In step S21, it is determined whether or not the vehicle 100 is expected to start. If the vehicle 100 is expected to start, it is expected that charging of the battery 4 will begin when the vehicle 100 starts, so the risk of battery drain is considered low. Therefore, if the vehicle 100 is expected to start in step S21, regardless of the decisions made in steps S22 and S24 described later, the wake-up request signal W1 is not blocked and the wake-up request signal W1 is transmitted (step S4).

[0031] Furthermore, the pre-configured ECU2 in step S21 is an ECU that operates when a specific operation is performed on the vehicle 100 by an important driver. In this case, if it is determined that relay should not be interrupted from the standpoint of convenience, etc., regardless of the decisions made in steps S22 and S24 described later, the system proceeds to step S4 and transmits the wake-up request signal W1 without interrupting its relay. If relay interruption has already occurred in such a case, the system resolves that state and proceeds to step S4, returning to the normal state of transmitting the wake-up request signal W1.

[0032] If step S21 is NO, step S22 determines the continuity of the wake-up request signal W1. Here, continuity is determined if the same wake-up request signal W1 from the same ECU2 is received consecutively (step S22: YES). If there is no continuity (step S22: NO), the relay of the wake-up request signal W1 is not interrupted, and the wake-up request signal W1 is transmitted (step S4).

[0033] In step S22, if there is continuity in the wake-up request signal W1 (step S22: YES), the CPU 31's real-time clock (RTC) performs a time count (step S23) to measure the elapsed time since the continuous wake-up request signal W1 began. If the measured time exceeds the set time Ta (step S24: YES), the relay of the wake-up request signal W1 is interrupted (step S3). If the measured time does not exceed the set time Ta (step S24: NO), the relay of the wake-up request signal W1 is not interrupted, and the wake-up request signal W1 is transmitted (step S4).

[0034] As shown in Figure 3, through this wake-up request relay unit 31W processing, if the same wake-up request signal W1 transmitted from one ECU2 to the gateway device 3 continues beyond the set time Ta, the gateway device 3 will stop relaying the wake-up request signal W1 to other ECU2s, regardless of whether there is an abnormality in the wake-up data, thereby avoiding the risk of battery depletion that can occur if the wake-up request signal W1 is continuously transmitted.

[0035] With the vehicle communication system 1 having these features, even if a situation arises where a wake-up request signal is continuously transmitted from one ECU 2, it is possible to suppress unnecessary power consumption without excessively increasing the processing capacity of the gateway device 3.

[0036] In the example described above, the case where a wake-up request signal is sent from one ECU2 was explained. However, even when the gateway device 3 wakes itself up by receiving all signals (for example, all CAN signals) sent from the communication line L and sends a wake-up request signal W1 to the target ECU2, if it determines that sending the wake-up request signal is unacceptable in terms of battery power consumption, it can perform a process to refrain from sending the wake-up request signal. This allows for the reduction of unnecessary power consumption without excessively increasing the processing capacity of the gateway device 3, as described above.

[0037] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and any design changes, etc., that do not depart from the gist of the present invention are also included. Furthermore, the above-described embodiments can be combined by utilizing each other's technologies, as long as there are no particular contradictions or problems in their purpose and configuration. [Explanation of symbols]

[0038] 1: Vehicle communication system 2: ECU 3: Gateway device 4: Battery 5: Vehicle equipment 20, 30: Microcontroller 21, 31: CPU 22, 32: ROM 23, 33: RAM 24, 34: External I / F 25, 35: Communication circuits 26, 36: Communication transceivers 21W: Wake-up request transmission unit 31W: Wake-up request relay unit W1: Wake-up request signal L (L1~L5): Communication line H: Power supply line 100: Vehicles

Claims

1. A vehicle communication system equipped with a gateway device that relays communication between multiple communication lines to which various ECUs are connected, The gateway device is The system has a sleep / wake function that, upon receiving a signal from the aforementioned communication line, transmits a wake-up request signal to transition the target ECU from a sleep state to a wake-up state. If it is determined that transmitting the wake-up request signal is unacceptable in terms of battery power consumption, the wake-up request signal will not be transmitted. A vehicle communication system characterized by transmitting the wake-up request signal regardless of the aforementioned determination when it is expected that the vehicle will start based on the wake-up request.

2. The gateway device is The system relays wake-up requests by transmitting the wake-up request signal to the target ECU in response to a wake-up request from one of the aforementioned ECUs. The vehicle communication system according to claim 1, characterized in that the relay is interrupted depending on the continuation status of a wake-up request from one of the ECUs.

3. The vehicle communication system according to claim 2, characterized in that the determination of the continuation status is made when the same wake-up request continues beyond a set time.

4. The gateway device is A vehicle communication system according to any one of claims 1 to 3, characterized in that, upon receiving the wake-up request signal from the ECU which has been set in advance, the wake-up request signal is transmitted regardless of the judgment made.

5. The gateway device is A vehicle communication system according to any one of claims 1 to 4, characterized in that it transmits the wake-up request signal when a specific operation is performed on the vehicle, regardless of the aforementioned determination.

6. A vehicle communication system equipped with a gateway device that relays communication between multiple communication lines to which various ECUs are connected, The gateway device is A first communication line connected to at least one of a predetermined number of first ECUs, and a second communication line connected to a second ECU different from the first ECU, and different from the first communication line, The communication between the first communication line and the second communication line is relayed. It receives power from the vehicle's battery, When the gateway device is in standby mode, upon receiving a first signal via the first communication line that causes the second ECU to transition from sleep mode to wake-up mode, the gateway device starts waking up and determines whether the first signal is being transmitted from the first ECU. If it is determined that the first signal is being transmitted from the first ECU, a second signal requesting the wake-up of the second ECU is transmitted to the second ECU via the second communication line. If it is determined that the first signal has not been transmitted from the first ECU, Based on whether the first signal received via the first communication line is continuous and the elapsed time since the continuity of the first signal began, it is determined whether the transmission of the second signal is acceptable in terms of the battery's power consumption. If it is determined that the transmission of the second signal is permissible, the second signal is transmitted. If it is determined that the transmission of the second signal is unacceptable, the transmission of the second signal will not be performed. A vehicle communication system characterized by the following features.

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