Vehicle control device

Abstract

To provide a vehicle control device capable of properly restarting an internal combustion engine during idling stop.SOLUTION: The vehicle control device includes a first ECU that executes automatic stopping of an internal-combustion engine during idling and executes restarting of the internal-combustion engine during the automatic stopping by driving a starter that cranks the internal-combustion engine, and a second ECU that monitors an operation state of the first ECU, wherein the first ECU outputs a state signal indicating that the operation state is normal to the second ECU, and the second ECU drives the starter to execute restarting of the internal-combustion engine during the automatic stopping in response to interruption of input of the state signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Regarding a vehicle control device, for example, Patent Document 1 describes that when an abnormality is detected in a microcomputer that performs idling stop control to automatically stop and restart the engine by driving the starter, driving of the starter is prohibited and the microcomputer is reset. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-209982 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above technology, when an abnormality is detected in the microcomputer while the engine is stopped, it takes time to restart the microcomputer by resetting it, and there is no guarantee that the microcomputer will return to normal after restarting, making it difficult to restart the engine properly.

[0005] SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an object to provide a vehicle control device that can appropriately restart an internal combustion engine that is stopped and idling. [Means for solving the problem]

[0006] The vehicle control device of the present invention has a first ECU that executes automatic stopping of an internal combustion engine while idling and drives a starter that cranks the internal combustion engine to restart the internal combustion engine while it is automatically stopped, and a second ECU that monitors the operating state of the first ECU, wherein the first ECU outputs a status signal to the second ECU indicating that the operating state is normal, and the second ECU drives the starter to restart the internal combustion engine while it is automatically stopped in response to an interruption in the input of the status signal. [Effects of the Invention]

[0007] According to the present invention, an internal combustion engine that is stopped while idling can be appropriately restarted. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram showing an example of a vehicle system. [Figure 2] FIG. 2 is a flowchart showing an example of the operation of an idling ECU (Electronic Control Unit). [Figure 3] FIG. 3 is a flowchart showing an example of the operation of the starter ECU. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Vehicle system configuration) 1 is a configuration diagram showing an example of a vehicle system S. The vehicle system S is installed in a vehicle such as a gasoline vehicle or a hybrid vehicle. The vehicle system S includes a vehicle control device 1, a drive unit 2, a starter 3, an engine 4, a sensor system 5, and a start switch SW.

[0010] The engine 4 is an example of an internal combustion engine, such as a gasoline engine or a diesel engine, and has a crankshaft 40 that transmits driving force for the vehicle.

[0011] The starter 3 is, for example, a starter motor, and cranks the engine 4. The starter 3 drives a crankshaft 40 when the engine 4 starts.

[0012] The drive device 2 drives the starter 3. The drive device 2 has, for example, an inverter circuit that drives the motor of the starter 3. The drive device 2 is started when the power is turned on by the vehicle control device 1, for example.

[0013] The sensor system 5 detects the amount of vehicle operation such as the accelerator pedal, brake pedal, and shift lever, and the vehicle running state such as the vehicle speed, using various sensors.

[0014] The vehicle control device 1 has an idling ECU 10, a starting ECU 11, and an engine ECU 12. The idling ECU 10, the starting ECU 11, and the engine ECU 12 are connected to a CAN (Controller Area Network) communication bus 13 and communicate with each other. Note that various other ECUs are also connected to the communication bus 13.

[0015] The idling ECU 10, the start ECU 11, and the engine ECU 12 each have a microcomputer 100, 110, and 120. The microcomputers 100, 110, and 120 each include a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM), and operate the CPU according to a program stored in the ROM.

[0016] In response to the driver turning on the start switch SW, the starter ECU 11 activates the drive unit 2 to drive the starter 3, and starts the engine 4 in cooperation with the engine ECU 12. The engine ECU 12 controls the output torque by adjusting the fuel injection amount and ignition timing of the engine 4 based on the detection values ​​of the sensor system 5 using the microcomputer 120.

[0017] The idling ECU 10 is an example of a first ECU, and executes idling stop control of the engine 4. When at least some of the detected values ​​of the sensor system 5 satisfy an idling stop condition, the idling ECU 10 executes automatic stop of the idling engine 4. Here, an example of the idling stop condition is, but is not limited to, when the shift lever is in the drive position and the brake pedal is depressed until the vehicle stops. The idling ECU 10 stops the engine 4 in cooperation with the engine ECU 12.

[0018] Furthermore, when at least some of the detected values ​​of the sensor system 5 satisfy the restart condition, the idling ECU 10 drives the starter 3 to restart the automatically stopped engine 4. Here, the restart condition includes, but is not limited to, that the brake pedal is not depressed.

[0019] However, if an abnormality occurs in the microcomputer 100 in the idling ECU 10, the engine 4 that has been automatically stopped cannot be restarted.

[0020] For this reason, the microcomputer 100 periodically inserts a pulse signal into the frame signal F that is transmitted to the communication bus 13. The pulse signal is a signal that alternates between signal values ​​of "0" and "1" at regular intervals. The microcomputer 100 generates the pulse signal only when the microcomputer 100 is in a normal operating state. The pulse signal is an example of a status signal that indicates that the operating state of the idling ECU 10 is normal.

[0021] Furthermore, the microcomputer 100 inserts a parameter (idling control state) indicating the state of the idling stop control into the frame signal F. For example, when the engine 4 is automatically stopped, the idling control state indicates "1," and when the engine 4 is running, the idling control state indicates "0."

[0022] The frame signal F is generated by a CAN controller (not shown) and is output from the idling ECU 10 to the starting ECU 11 via the communication bus 13 (see symbol K).

[0023] The start-up ECU 11 is an example of a second ECU. The start-up ECU 11 monitors the operating state of the idling ECU 10 using a pulse signal. The start-up ECU 11 receives a frame signal F from the communication bus 13 and extracts the idling control state and the pulse signal from the frame signal F.

[0024] The starter ECU 11 determines whether or not the engine 4 is automatically stopped based on the idling control state. If the engine 4 is automatically stopped, the starter ECU 11 determines whether or not a pulse signal is present.

[0025] In response to the interruption of the input of the pulse signal, the starter ECU 11 drives the starter 3 to restart the automatically stopped engine 4. For example, the starter ECU 11 drives the starter 3 by starting the drive device 2. The starter ECU 11 also restarts the engine 4 in cooperation with the engine ECU 12. This allows the starter ECU 11 to quickly restart the engine 4 without having to wait for the idling ECU 10 to return to normal operation.

[0026] In determining whether or not a pulse signal is present, the start-up ECU 11 checks the periodicity of the signal values ​​"0" and "1" of the pulse signal. For example, if the start-up ECU 11 determines that the pulse signal does not repeat the signal values ​​"0" and "1" at a predetermined cycle, it determines that the input of the pulse signal has been interrupted. In this case, the start-up ECU 11 determines that the operating state of the idling ECU 10 is abnormal.

[0027] If the idling ECU 10 is operating abnormally, the microcomputer 100 stops operating due to a CPU error. At this time, a monitoring device such as a watchdog timer circuit in the idling ECU 10 resets the CPU in response to the detected abnormality, and pulse signal generation is interrupted during the reset. As a result, the periodicity of the pulse signal values ​​"0" and "1" is lost. If the CPU error is resolved after the reset, the pulse signal output resumes normally. However, the start ECU 11 determines that the input of the pulse signal has been interrupted when it first detects the loss of periodicity in the pulse signal. In other words, the interruption of the input of the pulse signal also includes a momentary signal interruption.

[0028] Although a pulse signal is used as the status signal in this example, a counter signal may be used instead. The counter signal indicates a signal value that periodically counts up, for example, 0, 1, 2, . . .

[0029] (Idling ECU operation) 2 is a flowchart showing an example of the operation of the idling ECU 10. This operation is executed, for example, periodically while the engine 4 is automatically stopped.

[0030] First, the idling ECU 10 generates a pulse signal (step St11). Next, the idling ECU 10 generates a frame signal F including the pulse signal and the idling control state (automatic stop), and outputs it to the starter ECU 11 via the communication bus 13 (step St12).

[0031] Next, the idling ECU 10 determines whether the restart condition for the engine 4 is met based on the detection result of the sensor system 5 (step St13). If the restart condition is not met (No in step St13), this operation ends. On the other hand, if the restart condition is met (Yes in step St13), the idling ECU 10 drives the starter 3 (step St14) and restarts the engine 4 in cooperation with the engine ECU 12 (step St15).

[0032] (Start ECU operation) 3 is a flowchart showing an example of the operation of the starter ECU 11. This operation is executed, for example, periodically.

[0033] First, the starter ECU 11 determines whether or not the frame signal F has been received (step St1). If the frame signal F has not been received (No in step St1), this operation ends.

[0034] Furthermore, if the frame signal F is received (Yes in step St1), the starter ECU 11 determines whether the engine 4 is automatically stopped based on the idling control state in the frame signal F (step St2). If the engine 4 is running (No in step St2), this operation ends.

[0035] Furthermore, if the engine 4 is automatically stopped (Yes in step St2), the starter ECU 11 determines whether the pulse signal in the frame signal F has been interrupted (step St3). If the pulse signal has not been interrupted (No in step St3), the starter ECU 11 determines that the operating state of the idling ECU 10 is normal (step St7). Then, this operation ends.

[0036] If the pulse signal is interrupted (Yes in step St3), the starter ECU 11 determines that the operating state of the idling ECU 10 is abnormal (step St4). Next, the starter ECU 11 drives the starter 3 (step St5) and restarts the engine 4 in cooperation with the engine ECU 12 (step St6).

[0037] In this way, when the operating state of the idling ECU 10 is abnormal, the starter ECU 11 drives the starter 3 instead of the idling ECU 10 to restart the engine 4. This allows the vehicle control device 1 to appropriately restart the engine 4 that is stopped while idling.

[0038] The above-described embodiment is a preferred example of the present invention, but the present invention is not limited to this and can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0039] 1 vehicle control device, 3 starter, 4 engine (internal combustion engine), 10 idling ECU (first ECU), 11 starting ECU (second ECU)

Claims

[Claim 1] a first ECU that executes automatic stop of an idling internal combustion engine and restarts the internal combustion engine by driving a starter that cranks the internal combustion engine; a second ECU that monitors the operating state of the first ECU, The first ECU outputs a status signal indicating that the operating status is normal to the second ECU, the second ECU drives the starter in response to interruption of the input of the state signal, thereby restarting the internal combustion engine during the automatic stop. Vehicle control device.

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