Vehicle control device

Abstract

To downsize an electric oil pump device while enabling an engine to be started up with a starter motor.SOLUTION: When starting up an engine with a starter motor, starter start-up control allowing an electric oil pump device to start discharging operating oil is performed after determining that output voltage of a power source device or of input voltage of an electric oil pump device is equal to or larger than predetermined voltage at completion of cranking of the starter motor. Thus, a vehicle control device enables the electric oil pump device to normally perform, even in a case where the output voltage of the power source device is declined along with the cranking, without using a high functional device operational when voltage is low in the electric oil pump device and thereby being capable of downsizing the electric oil pump device while enabling an engine to be started up with a starter motor.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle equipped with a starter motor for starting an engine. [Background technology]

[0002] There is a well-known control device for a vehicle that includes an engine, a hydraulic clutch provided in a power transmission path between the engine and drive wheels, and an electric oil pump device that discharges hydraulic oil that serves as the source of hydraulic pressure to be supplied to the clutch. For example, Patent Document 1 discloses a power transmission device that engages the clutch using hydraulic pressure based on the hydraulic oil discharged from the electric oil pump device, and controls an electric motor that is connected to the power transmission path between the clutch and drive wheels so as to transmit power and output cranking torque, thereby starting the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5018971 Summary of the Invention [Problem to be solved by the invention]

[0004] A vehicle may be equipped with a starter motor used to start the engine, and the engine may be started using the starter motor. In this case, the output voltage of a power supply device that supplies power to drive the starter motor may temporarily drop. If this power supply device also supplies power to drive an electric oil pump device, the electric oil pump device may not operate normally when the electric oil pump device is driven to engage the clutch during engine start-up. To address this issue, it is possible to use an electric oil pump device that operates normally even when the input voltage of the electric oil pump device drops as the engine starts. In this case, it is necessary to use a high-performance device (= device) inside the electric oil pump device that can operate even when the voltage drops, such as by providing a boost power supply circuit inside the electric oil pump device or by providing an inverter in the electric oil pump device with a function that allows operation even at low voltages. However, this poses a problem in that it is difficult to reduce the size of the electric oil pump device due to the additional hardware configuration.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can accommodate starting of the engine using a starter motor while also enabling the miniaturization of an electric oil pump device. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a vehicle including: (a) an engine; a hydraulic clutch provided in a power transmission path between the engine and drive wheels; a starter motor used to start the engine; an electric oil pump device that discharges hydraulic oil that is the source of the hydraulic pressure supplied to the clutch; and a power supply device that supplies electric power to drive the starter motor and the electric oil pump device; and (b) when starting the engine using the starter motor, after completion of cranking by the starter motor, the output voltage of the power supply device or the input voltage of the electric oil pump device is A predetermined value for recovering from a state temporarily decreased due to the cranking and ensuring normal operation of the electric oil pump device.The hydraulic oil pump device includes a start control unit that performs starter start control to start discharging the hydraulic oil from the electric oil pump device after determining that the voltage is equal to or higher than a predetermined voltage.

[0007] In addition, a second invention is a vehicle control device according to the first invention, wherein when performing the starter start control, the start control unit starts the discharge of the hydraulic oil by the electric oil pump device, and then supplies the hydraulic pressure based on the hydraulic oil to the clutch to switch the clutch from a released state to an engaged state.

[0008] Furthermore, a third invention is a vehicle control device according to the first or second invention, wherein the start control unit starts the engine with the power supplied to each of the starter motor and the electric oil pump device, and when it determines that the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage after the cranking is completed, starts the discharge of the hydraulic oil by the electric oil pump device.

[0009] In addition, a fourth invention is a vehicle control device described in the third invention, in which the start control unit determines whether the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage after the cranking is completed, when a predetermined preparation time required for preparing the electric oil pump device to operate has elapsed from the time when the supply of power to the electric oil pump device is started.

[0010] In addition, a fifth invention is a vehicle control device described in the third or fourth invention, in which the start control unit determines whether the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage by determining whether the electric oil pump device has detected that the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage.

[0011] Further, a sixth aspect of the present invention is that in the vehicle control device described in the first or second aspect of the present invention, the start control unit starts starting the engine with the power supplied to the starter motor, and when it determines that the output voltage of the power supply unit is equal to or higher than the predetermined voltage after the cranking is completed, it starts supplying the power to the electric oil pump device and starts the electric oil pump device discharging the hydraulic oil.

[0013] Also, 7 The present invention is the first to third inventions. 6 In the vehicle control device described in any one of the above inventions, the start control unit is capable of performing clutch start control, which controls the clutch to transmit a cranking torque required for cranking to increase the rotational speed of the engine, controls an electric motor that is power-transmittably connected to a power transmission path between the clutch and the drive wheels and is driven by power supplied from a high-voltage power supply device that is arranged to be able to charge the power supply device, so as to output the cranking torque in conjunction with the cranking by the clutch, and controls the engine to start operating in conjunction with the cranking by the clutch, and the start control unit performs the starter start control when it is difficult to perform the clutch start control.

[0014] Also, 8 The invention is 7 In the vehicle control device according to the invention, a case where it is difficult to perform the clutch start control is when the engine is started for the first time after the vehicle is started.

[0015] Also, 9 The invention is 7 invention or 8 In the vehicle control device described in the invention, it is difficult to perform the clutch start control when the vehicle is in a predetermined extremely low temperature environment where it is determined that the electric motor cannot be controlled properly. [Effects of the Invention]

[0016] According to the first aspect of the present invention, when starting an engine using a starter motor, after cranking by the starter motor is completed, the output voltage of the power supply device or the input voltage of the electric oil pump device , a predetermined value for recovering from a state temporarily decreased due to cranking and ensuring normal operation of the electric oil pump device. After determining that the voltage is equal to or greater than a predetermined voltage, a starter startup control is performed to start discharging hydraulic oil from the electric oil pump device. Therefore, when the output voltage of the power supply device drops due to cranking, the electric oil pump device does not need to use a high-performance device inside the device that can operate even when the voltage drops. surely The electric oil pump device can operate normally, and therefore the size of the electric oil pump device can be reduced while still supporting engine starting using a starter motor.

[0017] Furthermore, according to the second invention, when starter startup control is performed, the electric oil pump device starts to discharge hydraulic oil, and then hydraulic pressure based on the hydraulic oil is supplied to the clutch, switching the clutch from a released state to an engaged state, thereby making it possible to prepare for the vehicle to start while also miniaturizing the electric oil pump device.

[0018] According to the third aspect of the present invention, engine start is initiated with power supplied to both the starter motor and the electric oil pump device, and when it is determined that the input voltage to the electric oil pump device is equal to or higher than a predetermined voltage after cranking is complete, the electric oil pump device begins to discharge hydraulic oil, so that when cranking is complete, power is already being supplied to the electric oil pump device, and once the input voltage is equal to or higher than the predetermined voltage, discharge of hydraulic oil begins quickly. This allows the clutch to be quickly engaged when hydraulic pressure based on the hydraulic oil is supplied to the clutch to switch it from a released state to an engaged state, improving responsiveness until the vehicle starts moving.

[0019] Furthermore, according to the fourth invention, after a predetermined preparation time required for preparing the electric oil pump device to operate has elapsed from the time when power supply to the electric oil pump device begins, it is determined whether the input voltage of the electric oil pump device is equal to or higher than a predetermined voltage after cranking is completed, so that when the input voltage is equal to or higher than the predetermined voltage, the discharge of hydraulic oil begins immediately without waiting for the predetermined preparation time.

[0020] Furthermore, according to the fifth invention, it is determined whether the electric oil pump device has detected that the input voltage of the electric oil pump device is equal to or higher than a predetermined voltage, thereby determining whether the input voltage of the electric oil pump device is equal to or higher than a predetermined voltage, thereby eliminating the need to use a highly functional device inside the electric oil pump device that can operate even when the voltage drops.

[0021] According to the sixth aspect of the present invention, when engine start is initiated with power supplied to the starter motor, and when it is determined that the output voltage of the power supply device is equal to or higher than a predetermined voltage after cranking is complete, power is supplied to the electric oil pump device and the electric oil pump device begins to discharge hydraulic oil, so that a state in which the electric oil pump device does not operate normally can be avoided when the output voltage of the power supply device drops due to cranking. As a result, when hydraulic pressure based on the hydraulic oil is supplied to the clutch and the clutch is switched from a released state to an engaged state, the clutch can be engaged while avoiding a state in which the electric oil pump device does not operate normally.

[0023] In addition, the above 7 According to the invention, when it is difficult to perform clutch start control, starter start control is performed, so that it is possible to start the engine using a starter motor separate from the engine start that is normally performed, while also making the electric oil pump device smaller.

[0024] In addition, the above 8According to the invention, it is difficult to perform clutch start control when starting the engine for the first time after starting the vehicle, so the engine can be started properly before warm-up is complete.

[0025] In addition, the above 9 According to the invention, it is difficult to perform clutch start control when the vehicle is in a predetermined extremely low temperature environment where it is determined that the electric motor cannot be controlled properly, so the engine can be started properly even in an extremely low temperature environment. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and control systems for various controls in the vehicle. [Figure 2] FIG. 2 is a diagram illustrating a hydraulic source that supplies hydraulic oil to a hydraulic control circuit and a destination of power supplied from a low-voltage battery. [Figure 3] FIG. 2 is a diagram illustrating the internal configuration of the electric oil pump device. [Figure 4] FIG. 4 is a diagram showing an example of a time chart when engine start control is executed. [Figure 5] 1 is a flowchart illustrating the main control operations of an electronic control device, and is a flowchart illustrating the control operations for reducing the size of an electric oil pump device while supporting engine starting using a starter motor. [Figure 6] 6 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 5 is executed. FIG. [Figure 7] FIG. 10 is a flowchart explaining the main control operations of the electronic control device, and is a flowchart explaining the control operations for reducing the size of the electric oil pump device while supporting engine start-up using a starter motor, and is an embodiment different from that of FIG. 5. [Figure 8] 8 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 7 is executed. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0028] Fig. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates the main parts of the control functions and control systems for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG that function as a power source SP. The vehicle 10 also has drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

[0029] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An electronic control unit (ECU) 90 (described later) controls an engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10, thereby controlling the engine torque Te of the engine 12.

[0030] The electric motor MG is a rotating electric machine, a so-called motor generator, that functions as both a motor that generates mechanical power from electric power and a generator that generates electric power from mechanical power. The electric motor MG is connected to a high-voltage battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The high-voltage battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The inverter 52 is controlled by an electronic control device 90 (described later), thereby controlling the MG torque Tm of the electric motor MG. The electric motor MG is driven by electric power supplied from the high-voltage battery 54 during power running. The electric motor MG supplies generated electric power to the high-voltage battery 54 during regeneration. For example, when the rotation direction of the electric motor MG is forward, which is the same as the rotation direction of the engine 12 when it is operating, the positive torque on the acceleration side is power running torque, and the negative torque on the deceleration side is regenerative torque. The above-mentioned electric power also refers to electric energy unless otherwise specified. Unless otherwise specified, the power also includes driving force, torque, and force.

[0031] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, housed within a case 18, which is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a clutch provided between the engine 12 and the electric motor MG in a power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20. The automatic transmission 24 is connected to the torque converter 22 and is interposed in the power transmission path between the torque converter 22 and the drive wheels 14. The automatic transmission 24 is a transmission provided between the electric motor MG and the drive wheels 14 in the power transmission path between the engine 12 and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26, which is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and the like. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22, and the like.

[0032] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be able to transmit power. That is, the electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, particularly to a power transmission path between the K0 clutch 20 and the drive wheels 14 so as to be able to transmit power. The electric motor MG is also connected to a power transmission path between the K0 clutch 20 and the torque converter 22 so as to be able to transmit power. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be able to transmit power without going through the K0 clutch 20.

[0033] The torque converter 22 includes a pump wheel 22a connected to the electric motor connecting shaft 36, and a turbine wheel 22b connected to a transmission input shaft 38, which is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid transmission device that transmits power from the power source SP from the electric motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 as a direct-coupled clutch that connects the pump wheel 22a and the turbine wheel 22b, i.e., that connects the electric motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0034] The automatic transmission 24 is a known planetary gear automatic transmission that includes, for example, one or more planetary gear devices (not shown) and an engagement device CB. The engagement device CB includes, for example, a plurality of hydraulic engagement devices, such as known friction engagement devices. Each engagement device CB has its torque capacity, or CB torque Tcb, changed by a CB hydraulic pressure PRcb, which is a regulated hydraulic pressure supplied from a hydraulic control circuit 56 provided in the vehicle 10, thereby switching between operating states, i.e., control states, such as an engaged state, a slip state, and a disengaged state.

[0035] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) with different speed ratios (also referred to as gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is established by engaging one of the engagement devices CB. The automatic transmission 24 switches between the established gear stages by an electronic control device 90 (described later) switching the control state of one of the engagement devices CB that is involved in shifting the automatic transmission 24 in response to the accelerator operation of the driver (=operator), the vehicle speed V, etc. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38 and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is equal to the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed as the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26 and is the output rotation speed of the automatic transmission 24.

[0036] The K0 clutch 20 is a hydraulic friction engagement device configured, for example, with a multi-plate or single-plate clutch. The K0 clutch 20 switches between control states such as an engaged state, a slip state, and a released state by changing the K0 torque Tk0, which is the torque capacity of the K0 clutch 20, using the K0 oil pressure PRk0, which is the adjusted oil pressure supplied from the hydraulic control circuit 56.

[0037] In the vehicle 10, when the K0 clutch 20 is engaged, the engine 12 and the torque converter 22 are connected to each other so that power can be transmitted between them. On the other hand, when the K0 clutch 20 is disengaged, power transmission between the engine 12 and the torque converter 22 is interrupted. Because the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 from the electric motor MG.

[0038] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Furthermore, regardless of the control state of the K0 clutch 20, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the drive wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order.

[0039] The vehicle 10 further includes an MOP 58 which is a mechanical oil pump, an electric oil pump 60 which is an electric oil pump device, a starter motor 62, a DC / DC converter 64, a low-voltage battery 66, a start button 68, and the like.

[0040] The MOP 58 is connected to the pump impeller 22a and is rotationally driven by a power source SP to discharge hydraulic oil OIL used in the power transmission device 16. The power source SP that rotationally drives the MOP 58 is the electric motor MG when the K0 clutch 20 is disengaged, and is at least the engine 12 when the K0 clutch 20 is engaged. The electric oil pump 60 discharges hydraulic oil OIL when an electric oil pump pump 72 (see FIGS. 2 and 3, described later) provided in the electric oil pump 60 is rotationally driven by an electric oil pump motor 70 (see FIGS. 2 and 3, described later) provided in the electric oil pump 60. The electric oil pump 60 is operated, for example, when the MOP 58 cannot operate or when the flow rate of hydraulic oil O by the MOP 58 is insufficient. The hydraulic oil O discharged by the MOP 58 and the electric oil pump 60 is supplied to the hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the electric oil pump 60.

[0041] The starter motor 62 is a starting motor used to start the engine 12. The starter motor 62 is a motor dedicated to rotating, i.e., cranking, the engine 12 when the engine 12 is started.

[0042] The DC / DC converter 64 is connected to the high-voltage battery 54. The low-voltage battery 66 is connected to the DC / DC converter 64 and is charged by the DC / DC converter 64 using power supplied from the high-voltage battery 54. The high-voltage battery 54 is a high-voltage battery that stores a higher voltage than the low-voltage battery 66, and is a high-voltage power supply device that is provided so as to be able to charge the low-voltage battery 66.

[0043] The start button 68 is a power switch operated by the driver to switch the state of power supply in the vehicle 10, i.e., the state of the vehicle power supply. The start button 68 is, for example, a momentary push button switch, and is pressed by the driver to the switch-on position. Every time the start button 68 is pressed to the switch-on position, it outputs a power switch signal PSon corresponding to the switch-on position to the electronic control unit 90, which will be described later. The electronic control unit 90 detects the operation of the start button 68 by the driver based on the power switch signal PSon.

[0044] The vehicle power supply state may be, for example, an off (= "OFF") state as an off state, an accessory on (= "ACC") state as a partial on state, and an ignition on (= "IG-ON") state as an on state. The "OFF" state is, for example, a power supply state in which the vehicle cannot be driven and some functions not related to vehicle driving are also disabled. The "ACC" state is, for example, a power supply state in which a combination meter (not shown) is turned off to disable vehicle driving but some functions not related to vehicle driving are enabled. The "IG-ON" state is, for example, a power supply state in which the combination meter is turned on to enable vehicle driving.

[0045] FIG. 2 is a diagram illustrating the hydraulic source that supplies hydraulic oil O to the hydraulic control circuit 56 and the destinations of power supplied from the low-pressure battery 66. In FIG. 2, the electric oil pump 60 includes an electric oil pump motor 70 and an electric oil pump pump 72 (see FIG. 3). The electric oil pump motor 70 is a motor dedicated to the electric oil pump 60 that drives the electric oil pump pump 72. The electric oil pump pump 72 is an electric oil pump that is driven by the electric oil pump motor 70 to discharge hydraulic oil O. The MOP 58 and the electric oil pump pump 72 are arranged in parallel due to the configuration of the oil passage through which the hydraulic oil O flows. The MOP 58 and the electric oil pump pump 72 each draw up hydraulic oil that has returned to an oil pan 100 located at the bottom of the case 18 through a strainer 102, which serves as a common suction port, and discharge the oil to their respective discharge oil passages 104, 106. The discharge oil passages 104, 106 are each connected to an oil passage provided in the hydraulic control circuit 56, for example, a line pressure oil passage 108 through which the line pressure PL flows. The discharge oil passage 104, through which the hydraulic oil OIL is discharged from the MOP 58, is connected to the line pressure oil passage 108 via an MOP check valve 110 provided in the hydraulic control circuit 56. The discharge oil passage 106, through which the hydraulic oil OIL is discharged from the electric oil pump pump 72, is connected to the line pressure oil passage 108 via an electric oil pump check valve 112 provided in the hydraulic control circuit 56.

[0046] The hydraulic control circuit 56 includes a line pressure oil passage 108, a check valve 110 for the MOP, and a check valve 112 for the electric oil pump, as well as a K0 solenoid SLk0, a regulator valve, a solenoid valve for the PL, and multiple CB solenoids, all of which are not shown.

[0047] The regulator valve adjusts the line pressure PL based on the hydraulic oil OIL discharged by at least one of the MOP 58 and the electric oil pump pump 72. The PL solenoid valve is, for example, a linear solenoid valve, and is controlled by an electronic control device 90 (described later) so as to output a pilot pressure corresponding to the input torque Tin to the automatic transmission 24, etc., to the regulator valve based on the modulator pressure. As a result, the line pressure PL is adjusted to a value corresponding to the input torque Tin to the automatic transmission 24, etc. The modulator pressure is, for example, oil pressure adjusted to a constant value by a modulator valve (not shown) using the line pressure PL as a source pressure.

[0048] The K0 solenoid SLk0 is a solenoid valve, particularly a linear solenoid valve, for the K0 clutch 20 that is controlled by an electronic control device 90 (described later) so as to use the line pressure PL as a source pressure and supply regulated K0 oil pressure PRk0 to the K0 clutch 20. The CB solenoid is provided corresponding to each engagement device CB, and, like the K0 solenoid SLk0, is a linear solenoid valve that uses the line pressure PL as a source pressure and supplies CB oil pressure PRcb.

[0049] The low-voltage battery 66 is connected to the electric oil pump 60 via an electric oil pump relay 120 provided in the vehicle. The low-voltage battery 66 is connected to the starter motor 62 via a starter relay 122 provided in the vehicle. The low-voltage battery 66 supplies power to the electric oil pump 60 when the electric oil pump relay 120 is turned on by a command from an electronic control device 90 (described later), i.e., when the electric oil pump relay 120 is energized and its contacts are closed. The low-voltage battery 66 supplies power to the starter motor 62 when the starter relay 122 is turned on by a command from the electronic control device 90 (described later), and its contacts are closed. In this way, the low-voltage battery 66 is a power supply device that supplies power to drive the electric oil pump 60 and the starter motor 62. An electric oil pump input voltage Vop, which is the input voltage to the electric oil pump 60, is 0 [V] when the electric oil pump relay 120 is off, and when the electric oil pump relay 120 is on, a low-voltage battery voltage Vbatlow, which is the output voltage of the low-voltage battery 66, is set to, for example, 12 [V]. A starter motor input voltage Vst, which is an input voltage to the starter motor 62, is 0 [V] when the starter relay 122 is in an OFF state, and is set to the low-voltage battery voltage Vbatlow when the starter relay 122 is in an ON state.

[0050] FIG. 3 is a diagram illustrating the internal configuration of the electric oil pump 60. In FIG. 3, the electric oil pump 60 includes the electric oil pump motor 70 and electric oil pump pump 72 described above, as well as a control power supply 74, an electric oil pump CPU 76, an electric oil pump inverter 78, and the like. A low-voltage battery voltage Vbatlow (see +B in FIG. 3), i.e., an electric oil pump input voltage Vop, is applied to the control power supply 74 and the electric oil pump inverter 78 via an electric oil pump relay 120. When the electric oil pump relay 120 is in the on state, the control power supply 74 supplies an operating voltage, for example, 5 V, to the electric oil pump CPU 76 as an electric oil pump internal control power supply voltage, which is the output voltage of the control power supply 74, based on the electric oil pump input voltage Vop. The control power supply 74 has an electric oil pump internal CPU reset function that initializes the electric oil pump CPU 76, i.e., resets the electric oil pump CPU 76, when the electric oil pump CPU 76 first starts operating after power is turned on. The electric oil pump CPU 76 is connected to an electric oil pump inverter 78, and controls the electric oil pump inverter 78 based on an electric oil pump control command signal Sop from an electronic control device 90, which will be described later. The electric oil pump inverter 78 is connected to the electric oil pump motor 70, and is controlled by the electric oil pump CPU 76 to operate the electric oil pump motor 70.

[0051] The vehicle 10 further includes an electronic control device 90 that includes a control device for the vehicle 10. The electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing in accordance with programs stored in the ROM in advance while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, clutch control, transmission control, etc. as necessary.

[0052] The electronic control device 90 receives various signals (for example, a power switch signal PSon, an engine rotation speed Ne which is the rotation speed of the engine 12, a turbine rotation speed Nt which is the same value as the AT input rotation speed Ni, an AT output rotation speed corresponding to the vehicle speed V, etc.) based on detection values ​​from various sensors and devices provided in the vehicle 10 (for example, a start button 68, an engine rotation speed sensor 80, a turbine rotation speed sensor 81, an output rotation speed sensor 82, an MG rotation speed sensor 83, an accelerator opening sensor 84, a throttle valve opening sensor 85, a brake switch 86, a battery sensor 87, an oil temperature sensor 88, a low-voltage battery sensor 89, etc.). The following signals are respectively supplied to the hydraulic control circuit 56: the power rotation speed No, the MG rotation speed Nm which is the rotation speed of the electric motor MG; the accelerator opening θacc which is the amount of accelerator operation by the driver which indicates the magnitude of the driver's acceleration operation; the throttle valve opening θth which is the opening of the electronic throttle valve; the brake-on signal Bon which is a signal indicating that the brake pedal for operating the wheel brakes is being operated by the driver; the battery temperature THbat, the battery charge / discharge current Ibat, and the battery voltage Vbat of the high-voltage battery 54; the hydraulic oil temperature THoil which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56; and the low-voltage battery voltage Vbatlow.

[0053] The electronic control device 90 calculates the battery charge amount SOC [%] based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat. The battery charge amount SOC is the charge amount of the high-voltage battery 54 and is a value indicating the state of charge of the high-voltage battery 54, i.e., a state-of-charge value. The electronic control device 90 calculates the chargeable power Win [W] and dischargeable power Wout [W] of the high-voltage battery 54 based on, for example, the battery temperature THbat and the battery charge amount SOC. The chargeable power Win of the high-voltage battery 54 is the maximum power that can be input, which specifies the limit on the input power of the high-voltage battery 54, and indicates the input limit, i.e., the charge limit, of the high-voltage battery 54. The dischargeable power Wout of the high-voltage battery 54 is the maximum power that can be output, which specifies the limit on the output power of the high-voltage battery 54, and indicates the output limit, i.e., the discharge limit, of the high-voltage battery 54.

[0054] The electronic control device 90 outputs various command signals (for example, an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Scb for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an electric oil pump control command signal Sop for controlling the electric oil pump 60, a starter control command signal Sst for controlling the starter motor 62, etc.) to each device provided in the vehicle 10 (for example, the engine control device 50, the inverter 52, the hydraulic control circuit 56, the electric oil pump 60, the starter motor 62, etc.).

[0055] Each hydraulic control command signal S will be described using the K0 hydraulic control command signal Sk0 as an example. The electronic control unit 90 calculates a K0 clutch command pressure Spk0, which is a command pressure for the K0 clutch 20 to supply the regulated K0 hydraulic pressure PRk0 from the hydraulic control circuit 56, as a command value for the K0 hydraulic pressure PRk0. The command pressure is a target hydraulic pressure commanded by the electronic control unit 90 for the hydraulic oil OIL supplied to the engagement device, and the actual hydraulic pressure, which is the actual hydraulic pressure supplied to the engagement device, changes depending on this command pressure. The electronic control unit 90 converts the K0 clutch command pressure Spk0 into a K0 command current value Sik0 for driving the K0 solenoid SLk0. The K0 command current value Sik0 is a command current for a solenoid driver, which is a drive circuit provided in the electronic control unit 90 that drives the K0 solenoid SLk0. The K0 hydraulic control command signal Sk0 is a drive current or drive voltage for the solenoid driver to drive the K0 solenoid SLk0 based on the K0 command current value Sik0. In other words, the K0 clutch command pressure Spk0 is converted into the K0 hydraulic control command signal Sk0 and output to the hydraulic control circuit 56. In this embodiment, for convenience, the K0 clutch command pressure Spk0 and the K0 hydraulic control command signal Sk0 are treated as the same.

[0056] In order to realize various controls in the vehicle 10, the electronic control device 90 is equipped with a power source control means, i.e., a power source control section 92, a clutch control means, i.e., a clutch control section 94, a transmission control means, i.e., a transmission control section 96, and a start control means, i.e., a start control section 98.

[0057] The power source control unit 92 includes a function as engine control means, i.e., engine control unit 92a, that controls the operation of the engine 12, and a function as electric motor control means, i.e., electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and is a hybrid control means, i.e., a hybrid control unit, that performs hybrid drive control using the engine 12 and the electric motor MG using these control functions.

[0058] The power source control unit 92 calculates the amount of driving demanded by the driver for the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand map. The driving demand map is a relationship that is experimentally or design-based and stored in advance, i.e., a predetermined relationship. The driving demand is, for example, the required driving torque Trdem at the drive wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the vehicle speed V at that time. The driving demand can also be the required driving force Frdem [N] at the drive wheels 14, the required AT output torque at the transmission output shaft 26, or the like. In calculating the driving demand, the AT output rotation speed No, or the like, can be used instead of the vehicle speed V.

[0059] The power source control unit 92 calculates a required system shaft torque Tsysdem for realizing the required drive torque Trdem, taking into consideration transmission loss, auxiliary load, the gear ratio γat of the automatic transmission 24, etc. The required system shaft torque Tsysdem is a required value of the system shaft torque Tsys. The system shaft torque Tsys is the torque on the electric motor connecting shaft 36, i.e., the transmission shaft torque. The system shaft torque Tsys is the torque of the power source torque Tsp that is transmitted to the drive wheels 14 via the automatic transmission 24, i.e., the torque used as the drive torque Tr. The power source control unit 92 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to realize the required system shaft torque Tsysdem.

[0060] When the required system shaft torque Tsysdem can be satisfied solely by the output of the electric motor MG, the power source control unit 92 establishes the motor drive mode, i.e., the BEV drive mode, as the drive mode for driving the vehicle 10. The BEV drive mode is an electric drive mode that enables motor driving, i.e., electric driving (=BEV driving), in which the vehicle runs using only the electric motor MG as the power source SP with the K0 clutch 20 disengaged and the engine 12 stopped. On the other hand, when the required system shaft torque Tsysdem cannot be satisfied without using at least the output of the engine 12, the power source control unit 92 establishes the engine drive mode, i.e., the HEV drive mode, as the drive mode. The HEV drive mode is a hybrid drive mode that enables engine driving, i.e., hybrid driving (=HEV driving), in which the vehicle runs using at least the engine 12 as the power source SP with the K0 clutch 20 engaged. On the other hand, even if the required system shaft torque Tsysdem can be satisfied by the output of the electric motor MG alone, the power source control unit 92 establishes the HEV drive mode as the drive mode when it is necessary to charge the high-voltage battery 54 or when it is necessary to warm up the engine 12, etc. Charging of the high-voltage battery 54 is necessary, for example, when the battery charge state of charge (SOC) falls below a specified range, or when charging the high-voltage battery 54 would improve energy efficiency even though the battery charge state of charge (SOC) is within the specified range.

[0061] The transmission control unit 96 determines whether to shift the automatic transmission 24 using, for example, a shift map, which is a predetermined relationship, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 as needed, i.e., depending on the result of the shift determination. In controlling the shift of the automatic transmission 24, the transmission control unit 96 performs shifting of the automatic transmission 24, for example, by switching a disengaging engagement device among the engagement devices CB to a disengaged state and switching an engaging engagement device among the engagement devices CB to an engaged state. The shift map is a predetermined relationship having shift lines on a two-dimensional coordinate system using, for example, vehicle speed V and required drive torque Trdem as variables, for determining whether to shift the automatic transmission 24. In the shift map, the AT output rotation speed No or the like may be used instead of the vehicle speed V, and the required drive force Frdem, accelerator opening θacc, throttle valve opening θth, or the like may be used instead of the required drive torque Trdem.

[0062] The start control unit 98 determines whether there is a request to start the engine 12, that is, to switch the control state of the engine 12 from a stopped state to an operating state. For example, the start control unit 98 determines whether there is an engine start request based on whether, in the BEV drive mode, the required system shaft torque Tsysdem has increased beyond a range that can be covered by the output of the electric motor MG alone, whether the engine 12 and the like need to be warmed up, or whether the high-voltage battery 54 needs to be charged.

[0063] When the start control unit 98 determines that there is an engine start request, it outputs a command to the clutch control unit 94 to control the K0 clutch 20 to start the engine 12, i.e., to execute engine start control CTst. The clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from the released state toward the engaged state so as to obtain a K0 torque Tk0 for transmitting the cranking torque Tcr to the engine 12. The cranking torque Tcr is a predetermined torque required for cranking the engine 12 to increase the engine rotation speed Ne.

[0064] When the start control unit 98 determines that there is an engine start request, it outputs a command to the power source control unit 92 to control the engine 12 and the electric motor MG to execute engine start control CTst. The power source control unit 92, particularly the electric motor control unit 92b, outputs an MG control command signal Sm to the inverter 52 in response to switching of the K0 clutch 20 to the engaged state, that is, in conjunction with cranking of the engine 12 by the K0 clutch 20. Furthermore, the power source control unit 92, particularly the engine control unit 92a, outputs an engine control command signal Se to the engine control device 50 in conjunction with cranking of the engine 12 by the K0 clutch 20 to start fuel supply, engine ignition, and the like.

[0065] When cranking the engine 12, a reaction torque is generated due to engagement of the K0 clutch 20. During BEV driving, this reaction torque causes a drop in the drive torque Tr due to the inertia of the engine 12 and other components during engine start. Therefore, when cranking the engine 12, the MG torque Tm is increased by the cranking torque Tcr transmitted via the K0 clutch 20. The MG torque Tm increased toward the cranking torque Tcr during engine start control CTst is the MG torque Tm for canceling out this reaction torque and for compensating for this reaction torque, i.e., the MG torque Tm for reaction force compensation. The cranking torque Tcr is the K0 torque Tk0 required for cranking the engine 12, and is the MG torque Tm required for cranking the engine 12 that flows from the electric motor MG side to the engine 12 side via the K0 clutch 20. The cranking torque Tcr is, for example, a constant torque that is predetermined based on, for example, the specifications of the engine 12, the starting method (start type) of the engine 12, or the like.

[0066] In other words, during the engine start control CTst during BEV driving, the electric motor MG outputs not only the MG torque Tm used as the drive torque Tr but also the MG torque Tm used as the cranking torque Tcr. Therefore, during BEV driving, it is necessary to ensure the cranking torque Tcr in preparation for the engine start control CTst to prevent a drop in the drive torque Tr during the engine start control CTst. Therefore, the range in which the required system shaft torque Tsysdem can be satisfied solely by the output of the electric motor MG is the torque range obtained by subtracting the cranking torque Tcr from the maximum torque that the electric motor MG can output, i.e., the maximum MG torque Tmmax. The upper limit of the system shaft torque Tsys during BEV driving, i.e., the MG torque Tm, is limited by the torque obtained by subtracting the cranking torque Tcr from the maximum MG torque Tmmax. The maximum MG torque Tmmax is the maximum value of the MG torque Tm, determined by the dischargeable power Wout of the high-voltage battery 54 and / or the rating of the electric motor MG.

[0067] FIG. 4 is a diagram showing an example of a time chart when the engine start control CTst is executed. In FIG. 4, time t1a indicates the time when the engine start control CTst is initiated, for example, when the driver further depresses the accelerator pedal during BEV driving, and thus an engine start request is detected. After the engine start control CTst is initiated, packing control of the K0 clutch 20, i.e., K0 packing control, is executed. The packing control is a control for bringing the friction engagement device into a packing-completed state, i.e., a packing-completed state, in which pack clearances in the friction engagement device's friction plates, etc., are reduced. The packing-completed state of the friction engagement device is a state in which the friction engagement device begins to have torque capacity by increasing the hydraulic pressure supplied to the friction engagement device from the packing-completed state. After the K0 packing control is completed, cranking is executed by the K0 clutch 20, which transmits cranking torque Tcr to the engine 12, to crank the engine 12.

[0068] After the engine rotation speed Ne is increased by K0 cranking, synchronization control is performed by the K0 clutch 20 to synchronize the engine rotation speed Ne with the MG rotation speed Nm, i.e., K0 synchronization control (see the solid line in FIG. 4). The engine rotation speed Ne is the rotation speed of the engine connecting shaft 34 and is equal to the input rotation speed of the K0 clutch 20. The MG rotation speed Nm is the rotation speed of the electric motor connecting shaft 36 and is equal to the output rotation speed of the K0 clutch 20. In other words, synchronizing the engine rotation speed Ne with the MG rotation speed Nm is the same as synchronizing the input rotation speed and output rotation speed of the K0 clutch 20. When the synchronization of the input rotation speed and output rotation speed of the K0 clutch 20, i.e., K0 synchronization, is completed (see time t2a), that is, when the K0 clutch 20 is switched to the engaged state, i.e., K0 engagement is completed, engine ignition and the like are initiated, and the engine 12 is initially fired (see the solid line in FIG. 4). After K0 synchronization is complete, K0 full engagement control is executed to maintain the K0 clutch 20 in a fully engaged state (see time t2a and thereafter). Thereafter, when the engine torque Te is stably output in accordance with the engine control command signal Se, the engine start control CTst is completed (see time t3a). In this embodiment, the engine start type in which the engine rotation speed Ne is increased to K0 synchronization using the K0 clutch 20 and the electric motor MG, and then the engine 12 is started by initial combustion, is referred to as a push start type. The push start type is a start type in which the engine rotation speed Ne is increased by cranking torque Tcr and the engine 12 is ignited after K0 synchronization is complete. In other words, this start type increases the engine rotation speed Ne using the K0 clutch 20 in a fuel-cut state, and then ignites the engine after K0 synchronization is complete.

[0069] In this embodiment, as shown by the dashed line in FIG. 4, an engine start type other than the push start type (see the solid line in FIG. 4) can be implemented. As shown by the dashed line in FIG. 4, when the engine rotation speed Ne is increased by K0 cranking, engine ignition and other processes are initiated early, causing the engine 12 to initially explode before K0 synchronization. As shown by the dashed line in FIG. 4, after K0 cranking ends, a post-cranking constant-pressure standby is executed in which the K0 torque Tk0 is reduced below the cranking torque Tcr and maintained at a predetermined torque Tk0f to wait for the K0 clutch 20 to switch to an engaged state. The K0 clutch command pressure Spk0 during the post-cranking constant-pressure standby is, for example, approximately the same as the K0 oil pressure PRk0 that maintains the K0 clutch 20 in a fully packed state or a slip state. This K0 clutch command pressure Spk0 is set to achieve the K0 torque Tk0 that does not disturb the complete explosion of the engine 12. During post-cranking constant-pressure standby, the engine speed Ne is increased solely by the combustion torque of the engine 12, not by the K0 torque Tk0. During post-cranking constant-pressure standby, when the engine 12 reaches a stable, self-sustaining rotation state due to combustion, i.e., when the engine 12 reaches a complete combustion state, K0 synchronization control is executed to complete K0 synchronization. K0 synchronization control may be initiated after the engine speed Ne reaches the MG rotation speed Nm. Therefore, the engine speed Ne after the initial combustion of the engine 12 is increased toward K0 synchronization by at least the engine torque Te. In this embodiment, an engine start type in which the engine 12 is started by initial combustion before K0 synchronization, for example, early in K0 cranking, is referred to as an early start method, or TDC start type. The TDC start type is a start method in which the engine 12 is caused to ignite during the process leading up to the completion of K0 synchronization, and the engine speed Ne is increased by at least the engine torque Te after the engine 12 has exploded. Although the period of engine start control CTst is essentially different between the push start type indicated by the solid line and the TDC start type indicated by the dashed line, for the sake of convenience, they are shown to be the same length in FIG.

[0070] 4, during engine start control CTst, the start control unit 98 performs clutch start control CTstclt, which controls the K0 clutch 20 to transmit cranking torque Tcr, controls the electric motor MG to output cranking torque Tcr in conjunction with cranking by the K0 clutch 20, and controls the engine 12 to start operation in conjunction with cranking by the K0 clutch 20. The start control unit 98 also selectively executes clutch start control CTstclt of the push start type and clutch start control CTstclt of the TDC start type.

[0071] The TDC start type requires a smaller cranking torque Tcr than the push start type because the engine 12's self-rotation increases the engine speed Ne, resulting in superior energy efficiency and starting responsiveness. On the other hand, the push start type is more likely to reduce starting shock than the TDC start type. For this reason, the start control unit 98 performs clutch start control CTstclt using the push start type in regions where starting shock is likely to be a problem, such as regions where the MG rotation speed Nm is low, or when shock sensitivity is likely to be high, such as when the automatic transmission 24 is in low gear.

[0072] Here, during the engine start control CTst, the required cranking torque Tcr tends to be large, for example, when the engine 12 is cold. Therefore, for example, after the system of the vehicle 10 is started, that is, after the vehicle power supply state transitions from the "OFF" state to the "IG-ON" state by operating the start button 68, when starting the engine 12 for the first time, it may be difficult to perform the clutch start control CTstclt. Alternatively, during the engine start control CTst, it may be difficult to appropriately control the electric motor MG if, for example, the dischargeable power Wout of the high-voltage battery 54 is small or if it is difficult to supply power from the high-voltage battery 54. Therefore, for example, when the vehicle 10 is in a predetermined extremely low-temperature environment where it is determined that the electric motor MG cannot be appropriately controlled, it may be difficult to perform the clutch start control CTstclt.

[0073] The vehicle 10 is equipped with a starter motor 62. Therefore, the start control unit 98 can perform clutch start control CTstclt when performing engine start control CTst, and can also perform starter start control CTstmtr, which is starting of the engine 12 using the starter motor 62. When it is difficult to perform clutch start control CTstclt, the start control unit 98 performs starter start control CTstmtr.

[0074] During the starter startup control CTstmtr, the startup control unit 98 switches the starter relay 122 to the ON state, and then outputs a starter control command signal Sst for operating the starter motor 62 while power is being supplied to the starter motor 62 from the low-voltage battery 66, thereby cranking the engine 12 by the starter motor 62. When the engine 12 has fully exploded, the startup control unit 98 cancels the starter control command signal Sst, thereby stopping cranking by the starter motor 62.

[0075] To transmit the power of the engine 12 to the drive wheels 14, the K0 clutch 20 must be switched to an engaged state. At this time, because the MOP 58 is not operating, the electric oil pump 60 must be operated to supply hydraulic oil OIL, which is the source of the K0 hydraulic pressure PRk0. During the starter startup control CTstmtr, the start control unit 98 switches the electric oil pump relay 120 to the on state, and then outputs an electric oil pump control command signal Sop to operate the electric oil pump motor 70 while power is being supplied to the electric oil pump 60 from the low-voltage battery 66, causing the electric oil pump 60 to discharge hydraulic oil OIL. When performing the starter startup control CTstmtr, the start control unit 98 starts discharging the hydraulic oil OIL using the electric oil pump 60, and then outputs a command to the clutch control unit 94 to supply the K0 clutch 20 with the K0 hydraulic pressure PRk0, which is based on the hydraulic oil OIL, and switch the K0 clutch 20 from a released state to an engaged state.

[0076] Incidentally, when the starter startup control CTstmtr is performed, the low-voltage battery voltage Vbatlow may drop during cranking by the starter motor 62. Because the low-voltage battery 66 also supplies power to the electric oil pump 60, there is a risk that the electric oil pump input voltage Vop may drop during the starter startup control CTstmtr, causing the electric oil pump 60 to malfunction. In response to this, it may be possible to use an electric oil pump 60 that operates normally even when the electric oil pump input voltage Vop drops. In this case, the addition of sophisticated devices, such as providing a boost power supply circuit inside the electric oil pump 60 or providing the electric oil pump inverter 78 with a function that enables it to operate even at low voltage, may make it difficult to reduce the size of the electric oil pump 60.

[0077] Therefore, in this embodiment, when the electric oil pump input voltage Vop drops during the starter startup control CTstmtr, the electric oil pump 60 automatically detects a low-voltage fail state, thereby eliminating the need for a sophisticated device within the electric oil pump 60. The low-voltage fail state is, for example, a state in which the electric oil pump input voltage Vop is below a low-voltage fail threshold Vfail, which will be described later. The electric oil pump 60 notifies the electronic control unit 90 that it has detected a low-voltage fail state. When the low-voltage battery voltage Vbatlow subsequently recovers from its low-voltage state, the detection of the low-voltage fail state is canceled, and the electric oil pump 60 returns to a state in which it can operate normally. The electronic control unit 90 does not output a command to operate the electric oil pump 60 while the electric oil pump 60 detects a low-voltage fail state during cranking of the engine 12. The electronic control unit 90 is configured to output a command to operate the electric oil pump 60 only after the low-voltage battery voltage Vbatlow has stabilized after cranking of the engine 12 is complete. This eliminates the need to use a sophisticated device inside the electric oil pump 60, which leads to a reduction in the size of the electric oil pump 60.

[0078] Returning to FIG. 3 , the electric oil pump CPU 76 has a function of monitoring the electric oil pump input voltage Vop. For example, the electric oil pump CPU 76 determines whether the electric oil pump input voltage Vop is equal to or greater than a low-voltage fail threshold Vfail, which is a predetermined voltage. In other words, the electric oil pump CPU 76 has a low-voltage fail detection function that detects whether the electric oil pump input voltage Vop is less than the low-voltage fail threshold Vfail. The electric oil pump CPU 76 turns off the electric oil pump low-voltage fail flag FLflv if the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail, and turns on the electric oil pump low-voltage fail flag FLflv if the electric oil pump input voltage Vop is less than the low-voltage fail threshold Vfail. The low-voltage fail threshold Vfail is, for example, a predetermined lower limit value of the electric oil pump input voltage Vop to ensure normal operation of the electric oil pump 60. The electronic control device 90 is supplied with an electric oil pump low voltage fail flag FLflv from the electric oil pump 60 (see FIGS. 1 and 3).

[0079] Returning to FIG. 1 , during the starter startup control CTstmtr, the startup control unit 98 determines whether the electric oil pump low voltage fail flag FLflv is turned off after the completion of cranking by the starter motor 62. Determining whether the electric oil pump low voltage fail flag FLflv is turned off is equivalent to determining whether the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail. In this way, the startup control unit 98 determines whether the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail by determining whether the electric oil pump 60 has detected that the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail. After determining that the electric oil pump low voltage fail flag FLflv is turned off after the completion of cranking by the starter motor 62, that is, after determining that the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail, the startup control unit 98 outputs an electric oil pump control command signal Sop to start the discharge of hydraulic oil OIL by the electric oil pump 60. When the electric oil pump relay 120 is in the on state, the electric oil pump input voltage Vop is set to the low-voltage battery voltage Vbatlow, so determining that the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail is the same as determining that the low-voltage battery voltage Vbatlow is equal to or greater than the low-voltage fail threshold Vfail.

[0080] Specifically, after starting up the system of the vehicle 10, the start control unit 98 switches the starter relay 122 to the ON state and also switches the electric oil pump relay 120 to the ON state. Thereafter, the start control unit 98 outputs a starter control command signal Sst for operating the starter motor 62. In this way, the start control unit 98 commences starting of the engine 12 with power being supplied from the low-voltage battery 66 to each of the starter motor 62 and the electric oil pump 60.

[0081] The start control unit 98 determines whether the engine 12 has reached a complete combustion state, that is, whether the start of the engine 12 has been completed. When the engine 12 reaches a complete combustion state, cranking by the starter motor 62 is stopped, so determining whether the start of the engine 12 has been completed is equivalent to determining whether cranking by the starter motor 62 has been completed.

[0082] When the start control unit 98 determines that the start of the engine 12 has been completed, it determines whether the electric oil pump 60 has recovered from the low voltage fail state, i.e., whether the electric oil pump low voltage fail flag FLflv is off.

[0083] When the start control unit 98 determines that the electric oil pump 60 has recovered from the low voltage fail state, it outputs an electric oil pump control command signal Sop for operating the electric oil pump 60, i.e., the electric oil pump motor 70. In this way, when the start control unit 98 determines that the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail after cranking by the starter motor 62 is completed, it starts discharging the hydraulic oil OIL from the electric oil pump 60. Thereafter, the start control unit 98 outputs a command to the clutch control unit 94 to switch the K0 clutch 20 from the released state to the engaged state.

[0084] Fig. 5 is a flowchart explaining the main parts of the control operation of the electronic control device 90, and is a flowchart explaining the control operation for reducing the size of the electric oil pump 60 while responding to the start of the engine 12 using the starter motor 62, and is executed after the system of the vehicle 10 is started by operating the start button 68, for example. Fig. 6 is a diagram showing an example of a time chart when the control operation shown in the flowchart of Fig. 5 is executed.

[0085] 5, each step of the flowchart corresponds to a function of the start control unit 98. In step (hereinafter, the term "step" will be omitted) S10, the starter relay 122 is switched to the ON state, and the electric oil pump relay 120 is switched to the ON state. Next, in S20, a starter control command signal Sst for operating the starter motor 62 is output. Next, in S30, it is determined whether starting of the engine 12 has been completed. If the determination in S30 is negative, S30 is repeatedly executed. If the determination in S30 is positive, it is determined in S40 whether the electric oil pump 60 has recovered from the low voltage fail state. If the determination in S40 is negative, S40 is repeatedly executed. If the determination in S40 is positive, in S50, an electric oil pump control command signal Sop for operating the electric oil pump 60, i.e., the electric oil pump motor 70, is output. Next, in S60, a command is output to switch the K0 clutch 20 from the released state to the engaged state. After that, when the switching of the K0 clutch 20 to the engaged state is completed, this routine is ended.

[0086] FIG. 6 is a diagram showing an example of a case where the starter activation control CTstmtr is executed when the system of the vehicle 10 is started. In FIG. 6, time t1b indicates the time when the system of the vehicle 10 is started. When the system of the vehicle 10 is started, the starter relay 122 is switched to the ON state, and the electric oil pump relay 120 is also switched to the ON state. The electric oil pump 60 is started by switching the electric oil pump relay 120 to the ON state. After the electric oil pump 60 is started, a predetermined preparation time TMf (= TM1 + TM2 + TM3) is required for the electric oil pump 60 to be in a state where it can accept commands from the electronic control device 90. "TM1" is the time from the time when the electric oil pump relay 120 is switched to the ON state to the time when the electric oil pump internal control power supply voltage rises to the operating voltage of the electric oil pump CPU 76. "TM2" is the time from when the electric oil pump internal control power supply voltage rises to when the electric oil pump CPU 76 has completed resetting, i.e., when the electric oil pump CPU 76 has completed preparation for operation. "TM3" is the time from when the electric oil pump CPU 76 has completed preparation to when the electric oil pump CPU 76 has completed preparation for receiving commands from the electronic control device 90. The predetermined preparation time TMf is the same as the system startup time in known electronic control devices and CPUs.

[0087] Thereafter, operation of the starter motor 62 is initiated by a command from the electronic control unit 90, and cranking of the engine 12 is initiated (see time t2b). At this time, the low-voltage battery voltage Vbatlow drops due to cranking, and when the electric oil pump input voltage Vop falls below the low-voltage fail threshold Vfail, the electric oil pump 60 recognizes this as a low-voltage fail state and transmits the turned-on electric oil pump low-voltage fail flag FLflv to the electronic control unit 90 (see time t3b and thereafter). When cranking of the engine 12 is completed (see time t4b), the low-voltage battery voltage Vbatlow rises, and the electric oil pump input voltage Vop becomes equal to or greater than the low-voltage fail threshold Vfail (see time t5b), the electric oil pump 60 is restored from the low-voltage fail state. At this time, the electric oil pump 60 notifies the electronic control unit 90 that it has restored from the low-voltage fail state by turning off the electric oil pump low-voltage fail flag FLflv. The electric oil pump 60 may immediately turn off the electric oil pump low voltage fail flag FLflv when the electric oil pump input voltage Vop becomes equal to or greater than the low voltage fail threshold Vfail. Alternatively, as shown in FIG. 6, the electric oil pump 60 may turn off the electric oil pump low voltage fail flag FLflv a predetermined recovery delay time TM4 after the electric oil pump input voltage Vop becomes equal to or greater than the low voltage fail threshold Vfail (see time t6b). The predetermined recovery delay time TM4 is, for example, a predetermined delay time for determining that the electric oil pump input voltage Vop has reliably become equal to or greater than the low voltage fail threshold Vfail. After cranking of the engine 12 is complete, the electronic control unit 90 confirms that the electric oil pump low voltage fail flag FLflv is off and outputs a command to operate the electric oil pump 60, switching the K0 clutch 20 to the engaged state (see time t6b and thereafter).

[0088] Referring to FIG. 6, the start control unit 98 determines whether or not the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail after cranking by the starter motor 62 is completed, when a predetermined preparation time TMf required for preparing the electric oil pump 60 for operation has elapsed from the time when the supply of power from the low-voltage battery voltage Vbatlow to the electric oil pump 60 has started.

[0089] As described above, according to this embodiment, after cranking by the starter motor 62 is completed, it is determined that the low-voltage battery voltage Vbatlow or the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail, and then the starter startup control CTstmtr is performed to start the discharge of hydraulic oil OIL by the electric oil pump 60. Therefore, when the low-voltage battery voltage Vbatlow drops due to cranking, the electric oil pump 60 can operate normally without using a high-performance device inside the electric oil pump 60 that can operate even when the voltage drops. Therefore, it is possible to reduce the size of the electric oil pump 60 while still being able to start the engine 12 using the starter motor 62.

[0090] Furthermore, according to this embodiment, when the starter startup control CTstmtr is performed, the electric oil pump 60 starts to discharge the hydraulic oil OIL, and then the K0 oil pressure PRk0 based on the hydraulic oil OIL is supplied to the K0 clutch 20, and the K0 clutch 20 is switched from the released state to the engaged state, so that the electric oil pump 60 can be made smaller while preparing for the vehicle 10 to start.

[0091] Furthermore, according to this embodiment, starting of the engine 12 is initiated with power being supplied from the low-voltage battery 66 to each of the starter motor 62 and the electric oil pump 60, and if it is determined that the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail after cranking by the starter motor 62 is completed, the electric oil pump 60 begins to discharge hydraulic oil OIL. Therefore, power is already being supplied to the electric oil pump 60 at the time cranking is completed, and once the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail, discharge of hydraulic oil OIL begins promptly. As a result, when the K0 clutch 20 is switched from a released state to an engaged state by supplying the K0 oil pressure PRk0 based on the hydraulic oil OIL to the K0 clutch 20, the K0 clutch 20 can be quickly engaged, thereby improving responsiveness until the vehicle starts moving.

[0092] Furthermore, according to this embodiment, after the predetermined preparation time TMf required for preparing the electric oil pump 60 to operate has elapsed since the supply of electric power from the low-voltage battery voltage Vbatlow to the electric oil pump 60 has started, it is determined whether the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail after cranking by the starter motor 62 is completed, so that when the electric oil pump input voltage Vop is equal to or greater than the low-voltage fail threshold Vfail, the discharge of the hydraulic oil OIL is started immediately without waiting for the predetermined preparation time TMf. This makes it possible to shorten the time from the start of starting the engine 12 to the completion of engagement of the K0 clutch 20.

[0093] Furthermore, according to this embodiment, it is determined whether the electric oil pump 60 has detected that the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail, thereby determining whether the electric oil pump input voltage Vop is equal to or greater than the low voltage fail threshold Vfail, so there is no need to use a highly functional device inside the electric oil pump 60 that can operate even when the voltage drops.

[0094] Furthermore, according to this embodiment, when it is difficult to perform the clutch start control CTstclt, the starter start control CTstmtr is performed, so that it is possible to start the engine 12 using a starter motor 62 that is separate from the start of the engine 12 that is normally performed, while also making the electric oil pump 60 smaller.

[0095] Furthermore, according to this embodiment, it is difficult to perform the clutch start control CTstclt when starting the engine 12 for the first time after starting the vehicle 10, so the engine 12 can be started properly before the warm-up is complete.

[0096] Furthermore, according to this embodiment, it is difficult to perform the clutch start control CTstclt when the vehicle 10 is in a predetermined extremely low temperature environment where it is determined that the electric motor MG cannot be properly controlled, and therefore the engine 12 can be properly started in an extremely low temperature environment.

[0097] Next, another embodiment of the present invention will be described. In the following description, parts common to the embodiments will be given the same reference numerals and the description thereof will be omitted. [Example]

[0098] In the first embodiment described above, during the starter startup control CTstmtr, the starter motor 62 cranks the engine 12 with power being supplied to each of the starter motor 62 and the electric oil pump 60. In the case of the first embodiment described above, when the electric oil pump 60 detects a low voltage fail state due to a drop in the low voltage battery voltage Vbatlow, the electric oil pump motor 70 is not operated until the low voltage fail state is released, and operation of the electric oil pump motor 70 is started after the electric oil pump 60 has returned to a state in which it can operate normally.

[0099] In this embodiment, during starter startup control CTstmtr, after cranking of the engine 12 by the starter motor 62 is completed, the electric oil pump relay 120 is kept in the OFF state until the low-voltage battery voltage Vbatlow returns to a specified value or higher, thereby preventing a low-voltage fail state from occurring in the electric oil pump 60. In this embodiment, after cranking is completed and the low-voltage battery voltage Vbatlow returns, the electric oil pump relay 120 is switched to the ON state to operate the electric oil pump 60, thereby eliminating the need for a sophisticated device inside the electric oil pump 60.

[0100] That is, in this embodiment, after the start control unit 98 determines that the low-voltage battery voltage Vbatlow is equal to or greater than the low-voltage fail threshold Vfail after cranking by the starter motor 62 is completed, the start control unit 98 outputs an electric oil pump control command signal Sop to start the discharge of hydraulic oil OIL by the electric oil pump 60. At this time, the electric oil pump relay 120 is switched to the ON state after the low-voltage battery voltage Vbatlow is restored. In this way, the start control unit 98 starts the start of the engine 12 with power supplied to the starter motor 62 from the low-voltage battery 66, and if the start control unit 98 determines that the low-voltage battery voltage Vbatlow is equal to or greater than the low-voltage fail threshold Vfail after cranking by the starter motor 62 is completed, the start control unit 98 starts the supply of power from the low-voltage battery 66 to the electric oil pump 60 to start the discharge of hydraulic oil OIL by the electric oil pump 60.

[0101] Specifically, the start control unit 98 switches the starter relay 122 to the ON state after starting up the system of the vehicle 10. The electric oil pump relay 120 is kept in the OFF state so that cranking by the starter motor 62 does not cause a drop in the low-voltage battery voltage Vbatlow, causing the electric oil pump 60 to enter a low-voltage failure state.

[0102] Thereafter, the start control unit 98 outputs a starter control command signal Sst for operating the starter motor 62. The start control unit 98 starts the engine 12 without supplying power from the low-voltage battery 66 to the electric oil pump 60.

[0103] When it is determined that the starting of the engine 12 is completed, the start control unit 98 determines whether the low-voltage battery voltage Vbatlow is equal to or greater than a specified value, for example, a low-voltage fail threshold Vfail.

[0104] If the start-up control unit 98 determines that the low-voltage battery voltage Vbatlow is equal to or greater than the low-voltage fail threshold Vfail, it switches the electric oil pump relay 120 to the ON state. The start-up control unit 98 then determines whether the electric oil pump 60 is malfunctioning, i.e., whether the electric oil pump fail flag FLfop is OFF. Abnormalities in the electric oil pump 60 include multiple types of electric oil pump abnormalities, such as an abnormality in which the electric oil pump 60 is in a low-voltage fail state (i.e., an abnormality in which the electric oil pump low-voltage fail flag FLflv is ON), an abnormality in the internal function of the electric oil pump 60, or a hardware failure such as a malfunction of the electric oil pump motor 70. If the electric oil pump 60 determines through its self-diagnosis function that none of the multiple types of electric oil pump abnormalities has occurred, it turns off the electric oil pump fail flag FLfop. If the electric oil pump 60 determines through its self-diagnosis function that any one of the multiple types of electric oil pump abnormalities has occurred, it turns on the electric oil pump fail flag FLfop. Therefore, in this embodiment, the electric oil pump failure flag FLfop is supplied from the electric oil pump 60 to the electronic control unit 90.

[0105] As explained in the first embodiment, after the electric oil pump 60 is started by switching the electric oil pump relay 120 to the on state, a predetermined preparation time TMf is required for the electric oil pump 60 to be in a state where it can accept commands from the electronic control unit 90. The predetermined preparation time TMf is a time required only for the electric oil pump 60. For this reason, the electric oil pump 60 outputs an on or off signal for the electric oil pump fail flag FLfop from the time when the electric oil pump CPU 76 has completed preparation for accepting commands from the electronic control unit 90.

[0106] If the start control unit 98 determines that the electric oil pump 60 is not abnormal, it outputs an electric oil pump control command signal Sop to operate the electric oil pump 60, i.e., the electric oil pump motor 70. In this way, if the start control unit 98 determines that the electric oil pump 60 is in a state in which it can operate normally after cranking by the starter motor 62 is completed, it starts discharging the hydraulic oil OIL from the electric oil pump 60. Thereafter, the start control unit 98 outputs a command to the clutch control unit 94 to switch the K0 clutch 20 from the released state to the engaged state.

[0107] Fig. 7 is a flowchart explaining the main parts of the control operation of the electronic control device 90, and is a flowchart explaining the control operation for reducing the size of the electric oil pump 60 while responding to the start of the engine 12 using the starter motor 62, and is executed after the system of the vehicle 10 is started by operating the start button 68, for example. Fig. 7 is an embodiment different from the flowchart of Fig. 5. Fig. 8 is a diagram showing an example of a time chart when the control operation shown in the flowchart of Fig. 7 is executed.

[0108] 7, each step of the flowchart corresponds to a function of the start control unit 98. In S10B, the starter relay 122 is switched to the ON state. Next, in S20B, a starter control command signal Sst for operating the starter motor 62 is output. Next, in S30B, it is determined whether the starting of the engine 12 has been completed. If the determination in S30B is negative, S30B is repeatedly executed. If the determination in S30B is positive, it is determined in S40B whether the low-voltage battery voltage Vbatlow is equal to or higher than a specified value. If the determination in S40B is negative, S40B is repeatedly executed. If the determination in S40B is positive, in S50B, the electric oil pump relay 120 is switched to the ON state. Next, in S60B, it is determined whether the electric oil pump 60 is abnormal. If the determination in S60B is negative, S60B is repeatedly executed. If the determination in S60B is positive, in S70B, an electric oil pump control command signal Sop is output to operate the electric oil pump 60, i.e., the electric oil pump motor 70. Next, in S80B, a command to switch the K0 clutch 20 from the released state to the engaged state is output. Thereafter, when the switching of the K0 clutch 20 to the engaged state is completed, this routine is ended.

[0109] FIG. 8 is a diagram showing an example of a case where the starter activation control CTstmtr is executed when the system of the vehicle 10 is started. In FIG. 8, time t1c indicates the time when the system of the vehicle 10 is started. When the system of the vehicle 10 is started, the starter relay 122 is switched to the ON state. Thereafter, operation of the starter motor 62 is started in response to a command from the electronic control device 90, and cranking of the engine 12 is initiated (see time t2c). At this time, the low-voltage battery voltage Vbatlow drops due to cranking, but the electric oil pump relay 120 remains in the OFF state and the electric oil pump 60 is not started, so a low-voltage fail state does not occur in the electric oil pump 60 (see time t2c-t4c). When cranking of the engine 12 is completed (see time t3c), the low-voltage battery voltage Vbatlow increases and returns to a specified value, for example, the normal voltage of the low-voltage battery 66, and the electric oil pump relay 120 is switched to the ON state (see time t4c). The electric oil pump 60 is started by switching the electric oil pump relay 120 to the ON state. After the electric oil pump 60 is started, a predetermined preparation time TMf (= TM1 + TM2 + TM3) is required for the electric oil pump 60 to be in a state where it can accept commands from the electronic control unit 90 (see time t4c to time t5c). When the electric oil pump CPU 76 completes preparations to accept commands from the electronic control unit 90 and an OFF signal for the electric oil pump fail flag FLfop is output from the electric oil pump 60 (see time t5c), the electronic control unit 90 outputs a command to operate the electric oil pump 60 and switches the K0 clutch 20 to the engaged state (see time t5c and onwards).

[0110] As described above, according to this embodiment, similar to the first embodiment, it is possible to start the engine 12 using the starter motor 62, while also achieving a reduction in the size of the electric oil pump 60.

[0111] Furthermore, according to this embodiment, when the engine 12 is started with power supplied from the low-voltage battery 66 to the starter motor 62, and when it is determined that the low-voltage battery voltage Vbatlow is equal to or greater than the low-voltage fail threshold Vfail after cranking by the starter motor 62 is completed, power is supplied from the low-voltage battery 66 to the electric oil pump 60, and the electric oil pump 60 begins to discharge hydraulic oil OIL. This makes it possible to avoid a state in which the electric oil pump 60 does not operate normally when the low-voltage battery voltage Vbatlow drops during cranking. As a result, when the K0 oil pressure PRk0 based on the hydraulic oil OIL is supplied to the K0 clutch 20 and the K0 clutch 20 is switched from the released state to the engaged state, it is possible to engage the K0 clutch 20 while avoiding a state in which the electric oil pump 60 does not operate normally, that is, without causing a low-voltage fail state in the electric oil pump 60.

[0112] Furthermore, according to this embodiment, if it is determined that the electric oil pump 60 is in a state in which it can operate normally after cranking by the starter motor 62 is completed, the electric oil pump 60 starts to discharge the hydraulic oil OIL, thereby ensuring that the electric oil pump 60 operates normally.

[0113] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0114] For example, in the above-described embodiment, the vehicle 10 was capable of performing clutch start control CTstclt and starter start control CTstmtr as engine start control CTst, but the present invention is not limited to this. For example, the present invention can be applied to any vehicle that is capable of performing at least starter start control CTstmtr.

[0115] Furthermore, in the above-described embodiment, it is assumed that the electric oil pump 60 can recover from a low voltage fail state or an abnormal state, but if the electric oil pump low voltage fail flag FLflv or the electric oil pump fail flag FLfop remains on, the starter startup control CTstmtr in an extremely low temperature environment may be interrupted using a timer that counts from the time the system of the vehicle 10 is started. In this case, the starter startup control CTstmtr may be performed again when the start button 68 is operated.

[0116] In the above-described embodiment, S40 in the flowchart of FIG. 5 may determine whether the electric oil pump 60 is in a state in which it can operate normally. That is, S40 in the flowchart of FIG. 5 may determine whether the electric oil pump 60 is not abnormal, i.e., whether the electric oil pump fail flag FLfop is off. Alternatively, S60B in the flowchart of FIG. 7 may simply determine whether the electric oil pump 60 has recovered from a low voltage fail state, i.e., whether the electric oil pump low voltage fail flag FLflv is off. In this way, the flowcharts of FIGS. 5 and 7 can be modified as appropriate.

[0117] In the above-described embodiment, a planetary gear automatic transmission is used as the automatic transmission 24, but the present invention is not limited to this. For example, the automatic transmission 24 may be a synchronous mesh parallel two-shaft automatic transmission including a known DCT (Dual Clutch Transmission), a known belt-type continuously variable transmission, or the like. Alternatively, the automatic transmission 24 does not necessarily have to be provided.

[0118] Furthermore, in the above-described embodiment, the torque converter 22 is used as the fluid transmission device, but this is not a limitation. For example, instead of the torque converter 22, another fluid transmission device, such as a fluid coupling that does not have a torque amplifying function, may be used as the fluid transmission device. Alternatively, the fluid transmission device does not necessarily have to be provided, and may be replaced with, for example, a starting clutch. In short, the present invention can be applied to any vehicle that includes an engine, a hydraulic clutch provided in a power transmission path between the engine and the drive wheels, a starter motor, an electric oil pump device that discharges hydraulic oil that forms the hydraulic pressure supplied to the clutch, and a power supply device that supplies electric power to drive the starter motor and the electric oil pump device.

[0119] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0120] 10: Vehicle 12: Engine 14: Drive wheel 20:K0 clutch (clutch) 54: High-voltage battery (high-voltage power supply) 60: Electric oil pump (electric oil pump device) 62: Starter motor 66: Low-voltage battery (power supply) 90: Electronic control device (control device) 98: Start control unit MG: Electric motor

Claims

1. A control device for a vehicle including an engine, a hydraulic clutch provided in a power transmission path between the engine and drive wheels, a starter motor used to start the engine, an electric oil pump device that discharges hydraulic oil that is the source of hydraulic pressure supplied to the clutch, and a power supply device that supplies electric power to drive the starter motor and the electric oil pump device, a start control unit that performs starter start control to start the discharge of the hydraulic oil by the electric oil pump device after determining that, when the engine is started using the starter motor, the output voltage of the power supply device or the input voltage of the electric oil pump device has recovered from a state that was temporarily reduced due to the cranking after the starter motor has completed cranking and is equal to or higher than a predetermined voltage that ensures normal operation of the electric oil pump device.

2. 2. The vehicle control device according to claim 1, wherein, when performing the starter start control, the start control unit starts the discharge of the hydraulic oil by the electric oil pump device, and then supplies the hydraulic pressure based on the hydraulic oil to the clutch to switch the clutch from a released state to an engaged state.

3. 3. The vehicle control device according to claim 1, wherein the start control unit starts starting the engine with the power supplied to each of the starter motor and the electric oil pump device, and when it determines that the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage after the cranking is completed, starts discharging the hydraulic oil by the electric oil pump device.

4. The vehicle control device described in claim 3, characterized in that the start control unit determines whether the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage after the cranking is completed, when a predetermined preparation time required to prepare the electric oil pump device for operation has elapsed from the time the supply of power to the electric oil pump device is started.

5. The vehicle control device according to claim 3 or 4, characterized in that the start control unit determines whether the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage by determining whether the electric oil pump device has detected that the input voltage of the electric oil pump device is equal to or higher than the predetermined voltage.

6. 3. The vehicle control device according to claim 1, wherein the start control unit starts starting the engine with the power supplied to the starter motor, and when it determines that the output voltage of the power supply device is equal to or higher than the predetermined voltage after the cranking is completed, starts supplying the power to the electric oil pump device to start discharging the hydraulic oil by the electric oil pump device.

7. The start control unit controls the clutch to transmit a cranking torque required for cranking to increase the rotational speed of the engine, controls an electric motor that is power-transmittably connected to a power transmission path between the clutch and the drive wheels and is driven by electric power supplied from a high-voltage power supply device that is provided so as to be able to charge the power supply device, so as to output the cranking torque in conjunction with the cranking by the clutch, and is capable of performing clutch start control that controls the engine to start operating in conjunction with the cranking by the clutch, 7. The vehicle control device according to claim 1, wherein the start control unit performs the starter start control when it is difficult to perform the clutch start control.

8. 8. The vehicle control device according to claim 7, wherein the case where it is difficult to perform the clutch start control is when the engine is started for the first time after the vehicle is started.

9. 9. The vehicle control device according to claim 7 or 8, characterized in that the case where it is difficult to perform the clutch start control is when the vehicle is in a predetermined extremely low temperature environment where it is determined that the electric motor cannot be properly controlled.

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