Control device for vehicle

Abstract

To inhibit diagnosis masking and re-startup of a high-voltage system due to a drop in auxiliary voltage.SOLUTION: There is provided a control device for a vehicle including: an engine; a starter for starting up the engine by cranking; a motor generator connected to the engine through a transmission device so as to allow power transmission; a high-voltage battery for supplying power to the motor generator; an auxiliary battery for supplying power to the starter; an engine control section for controlling the engine and the starter; and an integrated control section for controlling a high-voltage system including the high-voltage battery. The integrated control section is connected to the engine control section so as to communicate with each other. In a case where the vehicle is put into an ignition-on state, after one of a start of the engine and a startup of the high-voltage system is completed, the engine control section and the integrated control section start the other of the start of the engine and the startup of the high-voltage system.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a control device for a vehicle equipped with a mild hybrid system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-091911 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, when the vehicle's ignition is turned on, the engine is started and the high-voltage system is activated independently. The engine is started by cranking using a starter. The high-voltage system is a system that includes a high-voltage battery. The high-voltage system is activated by a control unit that controls the high-voltage system. This control unit and the starter are operated by power supplied from an auxiliary battery.

[0005] However, when starting the engine, cranking by the starter consumes a lot of energy, which causes a drop in the voltage of the auxiliary battery. Since the auxiliary battery supplies power not only to the starter but also to the control unit of the high-voltage system, if the engine is started and the high-voltage system is activated simultaneously, the drop in auxiliary voltage caused by cranking may cause a diagnostic mask or restart of the high-voltage system.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a vehicle control device that can suppress diagnostic masking and restart of a high-voltage system due to a drop in auxiliary voltage. [Means for solving the problem]

[0007] The present invention is a control device for a vehicle comprising an engine, a starter for starting the engine by cranking, a motor generator connected to the engine so as to be capable of transmitting power via a transmission device, a high-voltage battery for supplying power to the motor generator, an auxiliary battery for supplying power to the starter, an engine control unit for controlling the engine and the starter, and an integrated control unit for controlling a high-voltage system including the high-voltage battery, wherein the integrated control unit is communicatively connected to the engine control unit, and when the vehicle is in an ignition on state, the engine control unit and the integrated control unit initiate the other of the starting of the engine and the starting of the high-voltage system after one of the starting of the engine and the starting of the high-voltage system has been completed. Effect of the Invention

[0008] In the present invention, it is possible to suppress diagnostic masking and restart of the high voltage system due to a drop in auxiliary voltage. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a vehicle according to an embodiment. [Diagram 2] FIG. 2 is a flow chart showing the high-voltage system startup control. [Diagram 3] FIG. 3 is a flow chart showing the control before and after the completion of the startup of the high-voltage system. [Figure 4] FIG. 4 is a flow chart showing the control before and after the engine start is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control device according to an embodiment of the present invention will be specifically described below. Note that the present invention is not limited to the embodiment described below.

[0011] 1 is a diagram illustrating a vehicle according to an embodiment of the present invention. The vehicle 1 includes an engine (ENG) 2, a power transmission (T / M) 3, a starter 4, a motor generator (MG) 5, a high-voltage battery 6, a DC-DC converter 7, an auxiliary battery 8, an auxiliary device 9, an integrated ECU 21, an EFI-ECU 22, and an MG-ECU 23.

[0012] The vehicle 1 is equipped with an engine 2 and a motor generator 5 as power sources, and is a vehicle equipped with a mild hybrid system.

[0013] The engine 2 is a power source of the vehicle 1. Power output from the engine 2 is transmitted to wheels via a power transmission device 3. The power transmission device 3 includes a gear mechanism such as a transmission, and forms a power transmission path between the engine 2 and the wheels.

[0014] The starter 4 is a starter motor that starts the engine 2 by cranking. The starter 4 is driven by power supplied from an auxiliary battery 8. The shaft of the starter 4 is connected to the crankshaft of the engine 2 so as to be capable of transmitting power. When the starter 4 is driven, the shaft of the starter 4 rotates, thereby rotating the crankshaft of the engine 2, and the engine 2 starts.

[0015] The motor generator 5 functions as an electric motor and a generator. The motor generator 5 is connected to the engine 2 via a transmission device 10 so as to be capable of transmitting power. The transmission device 10 is a belt-type transmission device, and includes a pulley that rotates integrally with the crankshaft of the engine 2, a pulley that rotates integrally with the shaft of the motor generator 5, and a belt wound around these pulleys. The motor generator 5 starts the engine 2 via the transmission device 10. There are three methods for starting the engine 2: starting the engine 2 using the starter 4 alone, starting the engine 2 using the motor generator 5 alone, and starting the engine 2 using the starter 4 and the motor generator 5 together.

[0016] The motor generator 5 is driven by electric power supplied from a high-voltage battery 6. When the power of the engine 2 is insufficient, the motor generator 5 is driven as an electric motor to supplement the power of the engine 2. When the power of the engine 2 is sufficient, the motor generator 5 is driven as a generator to store electric power in an auxiliary battery 8. The motor generator 5 is electrically connected to a DCDC converter 7. The electric power generated by the motor generator 5 can be stored in the high-voltage battery 6.

[0017] The high-voltage battery 6 supplies power to the motor generator 5. The high-voltage battery 6 is composed of a secondary battery such as a lithium-ion battery. The rated voltage of the high-voltage battery 6 is 48 V. The high-voltage battery 6 is electrically connected to the motor generator 5 via an inverter 11. The high-voltage battery 6 is also electrically connected to the inverter 11 and the motor generator 5 via an SMR 12. The high-voltage system is composed of the high-voltage battery 6 and the SMR 12.

[0018] The SMR 12 is provided between the high-voltage battery 6 and the inverter 11. When the SMR 12 is in the ON state, the high-voltage battery 6 and the inverter 11 are electrically connected to each other. When the SMR 12 is in the OFF state, the high-voltage battery 6 and the inverter 11 are cut off so that no current flows between them. The SMR 12 switches between the ON state and the OFF state in response to a command signal from the integrated ECU 21.

[0019] The DCDC converter 7 is a power conversion device provided between the motor generator 5 and the auxiliary battery 8. The DCDC converter 7 is electrically connected between the high-voltage power line and the low-voltage line. The DCDC converter 7 steps down the voltage of the high-voltage power line and supplies it to the low-voltage line. The DCDC converter 7 is electrically connected to the auxiliary battery 8 and the auxiliary 9 via the low-voltage line.

[0020] The auxiliary battery 8 supplies power to the starter 4. The rated voltage of the auxiliary battery 8 is 12 V. The auxiliary battery 8 is electrically connected to the starter 4, the DCDC converter 7, and the auxiliary 9 via a low-voltage line. The auxiliary battery 8 is also electrically connected to the inverter 11 via the DCDC converter 7.

[0021] The integrated ECU 21 is an electronic control device that controls the high-voltage system. Signals from various sensors are input to the integrated ECU 21. The integrated ECU 21 executes various controls in response to the signals from the various sensors. For example, the integrated ECU 21 executes start-up control of the high-voltage system. The start-up of the high-voltage system means that the SMR 12 is turned on, the high-voltage battery 6 and the inverter 11 are electrically connected, and preparations for driving the high-voltage system are completed. Driving the high-voltage system includes driving the motor generator 5 and the DCDC converter 7. That is, the integrated ECU 21 controls the SMR 12 and the DCDC converter 7. The integrated ECU 21 includes an integrated control unit that controls the high-voltage system and a converter control unit that controls the DCDC converter 7.

[0022] The integrated ECU 21 is also connected to the EFI-ECU 22 so as to be able to communicate with the EFI-ECU 22. The integrated ECU 21 and the EFI-ECU 22 are configured so as to be able to transmit and receive information between the ECUs, for example, via a CAN or wired connection. Through communication with the EFI-ECU 22, the integrated ECU 21 can recognize that the engine 2 has started to start, that it is cranking, and that the engine 2 has completed combustion.

[0023] The EFI-ECU 22 is an electronic control device that controls the engine 2. The EFI-ECU 22 includes an engine control unit. The EFI-ECU 22 controls fuel injection and ignition timing in the engine 2. The EFI-ECU 22 executes starting control of the engine 2. In the engine starting control, when the starter 4 starts the engine 2 alone, the EFI-ECU 22 outputs a command signal to the starter 4 and performs cranking by the starter 4. In addition, the EFI-ECU 22 can recognize that the start-up process of the high-pressure system has started by communicating with the integrated ECU 21.

[0024] The MG-ECU 23 is an electronic control device that controls the motor generator 5. The MG-ECU 23 includes a motor control unit. The MG-ECU 23 outputs a command signal to the inverter 11 to control the driving of the motor generator 5. The inverter 11 has a plurality of switching elements that perform switching operations in response to the command signal from the MG-ECU 23. The MG-ECU 23 is connected to the integrated ECU 21 so as to be able to communicate with each other. The MG-ECU 23 and the integrated ECU 21 are configured so that information can be transmitted and received between the ECUs by, for example, a CAN or a direct line.

[0025] In the vehicle 1 configured as above, when the engine 2 is initially started by cranking using the starter 4, the energy consumed in cranking is large, and the voltage of the auxiliary battery 8 drops. The high-voltage system is started by the integrated ECU 21, but if the high-voltage system is started and the engine is started simultaneously, the auxiliary voltage may drop to a voltage at which the microcomputer of the integrated ECU 21 is reset if the auxiliary voltage drop is large. If the microcomputer of the integrated ECU 21 is reset, an unexpected system abnormality occurs due to inconvenience such as the SMR 12 being in an off state. Even if the microcomputer of the integrated ECU 21 is not reset, the high-voltage system is started in a diagnostic mask state in which the auxiliary voltage is lowered, and therefore the high-voltage system soundness check at the time of start-up is not performed. In this case, the vehicle continues to run in a situation where safety is not guaranteed. Therefore, in order to avoid this, the vehicle 1 is configured to perform the start control of the engine 2 and the start control of the high-voltage system in series. Specifically, the start of the engine 2 is started after the start of the high-voltage system is completed. Alternatively, the start process of the high-voltage system is started after the start of the engine 2 is completed. When the start-up of the high voltage system is completed before the engine is started, the drop in the auxiliary battery 8 can be suppressed by operating the DCDC converter 7.

[0026] 2 is a flow chart showing a flow of high-pressure system startup control. The control shown in FIG.

[0027] The integrated ECU 21 determines whether or not there is a start request from the user of the vehicle 1 (step S1). In step S1, it is determined whether or not the ignition has been switched from an off state to an on state. Alternatively, it is determined whether or not the start switch of the vehicle 1 has been turned on.

[0028] If it is determined that there is no start request from the user of the vehicle 1 (step S1: No), this control routine ends.

[0029] When it is determined that a start request has been made by the user of the vehicle 1 (step S1: Yes), the integrated ECU 21 determines whether the engine 2 has completely exploded (step S2). In step S2, it is determined whether the starting of the engine 2 has been completed. The integrated ECU 21 determines whether the starting of the engine 2 has been completed based on a signal input from the EFI-ECU 22.

[0030] If it is determined that the engine 2 is in a complete combustion state (step S2: Yes), the integrated ECU 21 starts a startup process for the high-voltage system (step S3). In step S3, the high-voltage system including the high-voltage battery 6 and the SMR 12 is started. The integrated ECU 21 outputs a command signal to the SMR 12 to turn on the SMR 12. After the process of step S3 is performed, this control routine ends.

[0031] If it is determined that the engine 2 has not completely exploded (step S2: No), the integrated ECU 21 determines whether or not the engine 2 is being cranked (step S4). In step S4, it is determined whether or not the engine 2 is being cranked by the starter 4. The integrated ECU 21 determines whether or not the engine 2 is being cranked based on a signal input from the EFI-ECU 22.

[0032] If it is determined that the engine 2 is being cranked (step S4: Yes), the integrated ECU 21 waits for the high-pressure system to start (step S5). In step S5, the start of the high-pressure system is prohibited, and the engine start is prioritized. After the process of step S5 is performed, this control routine ends.

[0033] If it is determined that the engine 2 is not being cranked (step S4: No), the integrated ECU 21 determines whether or not the engine 2 has not yet been started (step S6). In step S6, it is determined whether or not the engine 2 is in a stopped state and engine start control has not been started. The integrated ECU 21 determines whether or not the engine 2 is in a stopped state and engine start control has not been started, based on a signal input from the EFI-ECU 22.

[0034] If it is determined that the engine 2 has not yet started (step S6: No), this control routine ends.

[0035] If it is determined that the engine 2 has not yet been started (step S6: Yes), the integrated ECU 21 starts the startup process of the high-pressure system (step S7) and issues a request to wait for cranking (step S8). In step S7, startup control of the high-pressure system is performed. In step S8, a request to wait for cranking is sent from the integrated ECU 21 to the EFI-ECU 22. The integrated ECU 21 starts startup control of the high-pressure system and requests the EFI-ECU 22 to wait for cranking by the starter 4. After the process of step S8 is executed, this control routine ends.

[0036] 3 is a flow chart showing the control before and after the completion of the start-up of the high-pressure system. The control shown in FIG.

[0037] The integrated ECU 21 determines whether or not there is a start request from the user of the vehicle 1 (step S11). The process of step S11 is similar to the process of step S1 shown in FIG.

[0038] If it is determined that there is no start request from the user of the vehicle 1 (step S11: No), this control routine ends.

[0039] When it is determined that a start request has been made by the user of the vehicle 1 (step S11: Yes), the integrated ECU 21 determines whether or not the start-up of the high-pressure system has been completed (step S12). In step S12, it is determined whether or not the start-up process of the high-pressure system has been completed before starting the engine start. The integrated ECU 21 determines whether or not the start-up process of the high-pressure system has been completed before starting cranking by the starter 4.

[0040] If it is determined that the start-up of the high-pressure system is completed (step S12: Yes), the integrated ECU 21 starts cranking by the starter 4 (step S13). In step S13, starting of the engine 2 is started after the start-up of the high-pressure system is completed. The integrated ECU 21 outputs a command signal to the EFI-ECU 22 to permit initial cranking of the engine 2. The EFI-ECU 22 outputs a command signal to the starter 4 based on the signal from the integrated ECU 21 to start cranking by the starter 4. After the processing of step S13 is performed, this control routine ends.

[0041] If it is determined that the startup of the high-pressure system is not completed (step S12: No), the integrated ECU 21 puts the cranking of the engine 2 on hold (step S14). In step S14, the initial cranking of the engine 2 is prohibited until the startup of the high-pressure system is completed. The integrated ECU 21 outputs a command signal to the EFI-ECU 22 to prohibit the initial cranking of the engine 2 until the startup of the high-pressure system is completed. The EFI-ECU 22 puts the initial cranking of the engine 2 on hold based on the command signal from the integrated ECU 21. After the processing of step S14 is performed, this control routine ends.

[0042] 4 is a flow chart showing the control before and after the engine start is completed. The control shown in FIG.

[0043] The integrated ECU 21 determines whether or not there is a start request from the user of the vehicle 1 (step S21). The process of step S21 is similar to the process of step S1 shown in FIG.

[0044] If it is determined that there is no start request from the user of the vehicle 1 (step S21: No), this control routine ends.

[0045] When it is determined that a start request has been made by the user of the vehicle 1 (step S21: Yes), the integrated ECU 21 determines whether or not the starting of the engine 2 has been completed (step S22). In step S22, it is determined whether or not the starting of the engine 2 has been completed before the start-up process of the high-pressure system is started. The integrated ECU 21 determines whether or not the starting of the engine 2 has been completed before starting the start-up process of the high-pressure system.

[0046] If it is determined that the starting of the engine 2 is completed (step S22: Yes), the integrated ECU 21 starts the startup process of the high-pressure system (step S23). The process of step S23 is similar to the process of step S3 shown in Fig. 2. After the process of step S23 is performed, this control routine ends.

[0047] If it is determined that the starting of the engine 2 is not completed (step S22: No), this control routine ends. The integrated ECU 21 cranks the engine 2 for the first time, and prohibits the start of the high-pressure system until the starting of the engine 2 is completed.

[0048] As described above, according to the embodiment, the engine start control and the high-voltage system start control are arranged in series, so that the period during which the voltage of the auxiliary battery 8 drops due to engine start does not overlap with the period during which control of the high-voltage system is performed. As a result, both controls are performed without interference, so that diagnostic masking and restart of the high-voltage system due to a drop in the auxiliary voltage can be suppressed. [Explanation of symbols]

[0049] 1 vehicle 2 Engine (ENG) 3 Power transmission device (T / M) 4 Starter 5 Motor generator (MG) 6 High voltage battery 7 DC-DC Converter 8 Auxiliary Battery 9 Auxiliary Equipment 10 Transmission 11 Inverter 12 SMR 21 Integrated ECU 22 EFI-ECU 23 MG-ECU

Claims

[Claim 1] The engine, a starter for starting the engine by cranking; a motor generator connected to the engine via a transmission device so as to be capable of transmitting power; a high-voltage battery that supplies power to the motor generator; an auxiliary battery that supplies power to the starter; an engine control unit that controls the engine and the starter; an integrated control unit for controlling a high voltage system including the high voltage battery; A vehicle control device comprising: the integrated control unit is communicably connected to the engine control unit, When the vehicle is in an ignition-on state, the engine control unit and the integrated control unit start the other of the engine start and the high-pressure system start after one of the engine start and the high-pressure system start is completed. A vehicle control device comprising:

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