Electric vehicle control device

Abstract

To provide an electric-vehicular control apparatus capable of easily producing a target output quickly after an internal combustion engine starts.SOLUTION: A control apparatus 20 of an electric vehicle 1 performs: executing first learning control to learn an intake air volume at a start of an internal combustion engine 2 on the basis of a difference between a first output that calculates an output of the engine at start estimated on the basis of a water temperature Wt of the engine and a second output being an output of the engine driven by a first rotary electric machine when the first rotary electric machine driving the engine to motoring; and controlling a throttle so as to realize an intake air volume learned by the first learning control, when starting the engine.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control device for an electric vehicle. [Background technology]

[0002] Conventionally, there are known control devices for electric vehicles equipped with an internal combustion engine and a generator capable of driving the internal combustion engine (see, for example, Patent Document 1 and Patent Document 2). The control device for an electric vehicle in Patent Document 1 uses a friction torque learning value corresponding to the coolant temperature of the internal combustion engine in order to stabilize the idle speed after the internal combustion engine is started. In addition, the control device for an electric vehicle in Patent Document 2 detects the friction torque when cranking the internal combustion engine and starts the internal combustion engine by adding a torque equivalent to this friction torque. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-155357 A [Patent Document 2] JP 2015-164831 A Summary of the Invention [Problem to be solved by the invention]

[0004] The control device for an electric vehicle in Patent Document 1 cannot correct the torque when starting the internal combustion engine. Therefore, there is a risk that the output of the internal combustion engine will decrease immediately after starting the internal combustion engine. On the other hand, in the control device for an electric vehicle in Patent Document 2, there is a risk that the output of the internal combustion engine will be insufficient at the time of starting due to changes in oil temperature and water temperature. This may cause the internal combustion engine to fail to start, or even if the internal combustion engine does start, it may take time for the internal combustion engine to reach a target output after starting. In such a control device for an electric vehicle, it is preferable that the internal combustion engine can quickly achieve a target output after starting so that the generator can generate electricity immediately after starting the internal combustion engine.

[0005] An object of the present disclosure is to provide a control device for an electric vehicle that can easily achieve a target output quickly after an internal combustion engine starts. [Means for solving the problem]

[0006] The control device for an electric vehicle according to the present disclosure is a control device for an electric vehicle having an internal combustion engine including a throttle valve and a first rotating electric machine capable of driving the internal combustion engine. The period before firing for starting an internal combustion engine. The first output is calculated as the output at the time of startup, and the first rotating electric machine drives the internal combustion engine for motoring. , internal combustion engine The control device for an electric vehicle executes a first learning control for learning an intake air amount at the start of the internal combustion engine based on a difference between the first output and a second output, which is an output of the internal combustion engine driven by the first rotating electric machine at the start of the internal combustion engine. No. 1. The throttle valve is controlled to achieve the intake air volume learned by learning control. After that, fuel injection and firing are performed to start the internal combustion engine. .

[0007] According to this control device for an electric vehicle, the intake air amount at the start of the internal combustion engine can be accurately learned before the start of the internal combustion engine by the first learning control based on the difference between the first output calculated based on the water temperature and the second output, which is the output of the first rotating electric machine when the first rotating electric machine actually drives the internal combustion engine. This makes it easier for the internal combustion engine to quickly achieve the target output after it has started. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a control device for an electric vehicle that is likely to quickly produce a target output after the internal combustion engine has started. [Brief description of the drawings]

[0009] [Figure 1] 1 is a system diagram of an electric vehicle according to an embodiment of the present disclosure. [Diagram 2] 1 is a system diagram of an internal combustion engine according to an embodiment of the present disclosure. [Diagram 3]4 is a flowchart showing a control procedure of a control device for an electric vehicle according to an embodiment of the present disclosure. [Figure 4] 4 is a timing chart showing the output and rotation speed of the internal combustion engine when controlled by the control device for an electric vehicle according to an embodiment of the present disclosure.

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the longitudinal direction of a vehicle is indicated as Q in the drawings, the front is indicated as F, the width direction of the vehicle is indicated as P in the drawings, and the right side as viewed from the rear of the vehicle is indicated as R.

[0011] As shown in Fig. 1, the electric vehicle 1 according to this embodiment is a four-wheel drive plug-in hybrid electric vehicle (PHEV). The electric vehicle 1 has an internal combustion engine (ENG) 2, a generator (an example of a first rotating electric machine: GEN) 4, a front motor (an example of a second rotating electric machine: FrM) 6, a rear motor (RM) 8, a driving battery (BT) 10, a control device (HVECU) 20, an accelerator pedal 21, and an external charging device 22. In this embodiment, the electric vehicle 1 is an internal combustion engine transversely mounted electric vehicle 1 in which the crankshaft of the internal combustion engine 2 is arranged to extend in the vehicle width direction.

[0012] In the electric vehicle 1 of this embodiment, the front motor 6 drives the front wheel drive shaft 12a of the front wheels 12 via a transaxle 16. The rear motor 8 drives the rear wheel drive shaft 14a of the rear wheels 14 via a reduction gear 8c. The front motor 6 is connected to the drive battery 10 via a front inverter 18, and is supplied with electric power (second electric power) from the drive battery 10.

[0013] The front inverter 18 has a front motor control device (FrMCU) 6a and a generator control device (GCU) 4a that controls the generator 4. The front motor control device 6a receives signals from the control device 20 and controls the regeneration and power running of the front motor 6 so that the front motor 6 is in a desired operating state. The rear motor 8 is similarly connected to the drive battery 10 via the rear inverter 8b and is supplied with power (second power) from the drive battery 10. The rear inverter 8b has a rear motor control device (RMCU) 8a. The rear motor control device 8a receives signals from the control device 20 and controls the regeneration and power running of the rear motor 8 so that the rear motor 8 is in a desired operating state.

[0014] As shown in FIG. 2, the internal combustion engine 2 has a throttle valve 2b, an intake port 2c, a fuel injection valve 2d, a water passage 2e, a water temperature sensor (an example of a water temperature detector) 2f, an oil pan 2g, and an oil temperature sensor (an example of an oil temperature detector) 2h. In this embodiment, the internal combustion engine 2 is a multi-injection type gasoline engine. The internal combustion engine 2 injects fuel using a fuel injection valve 2d arranged in the intake port 2c, and adjusts the intake air amount using the throttle valve 2b to adjust the output. Specifically, the internal combustion engine 2 obtains the atmospheric temperature detected by an air flow sensor (not shown) from the target charging efficiency Ec and calculates the target intake air amount Qt by the engine control device 2a. The engine control device 2a calculates the target throttle flow rate Qth from the target intake air amount Qt. The engine control device 2a multiplies the target throttle flow rate Qth by a throttle flow rate coefficient Kth to calculate the throttle opening ThO. In this manner, the engine control device 2a adjusts the throttle opening ThO of the throttle valve 2b, thereby adjusting the amount of intake air supplied to the internal combustion engine 2. The internal combustion engine 2 may be a direct injection gasoline engine. The internal combustion engine 2 may also be a gasoline engine that uses both a multi-injection system and a direct injection system. Furthermore, the control of the throttle valve 2b may be performed by the control device 20.

[0015] The water passage 2e is a passage through which cooling water flows to cool the internal combustion engine 2. After cooling the internal combustion engine 2, the water passage 2e passes through a radiator (not shown) and returns to the internal combustion engine 2. The water temperature sensor 2f is provided on the water passage 2e and detects the temperature of the cooling water flowing through the water passage 2e. In this embodiment, the water temperature sensor 2f is provided in the water passage 2e provided in the cylinder block, but the water temperature sensor 2f may be provided anywhere on the water passage 2e as long as it can detect the temperature of the cooling water (water temperature Wt). The oil pan 2g collects oil supplied to the internal combustion engine 2. The internal combustion engine 2 is provided with an oil passage (not shown) that lubricates rotating parts such as the crankshaft and cools pistons and the like. The oil temperature sensor 2h detects the temperature of the oil (oil temperature Ot). In this embodiment, the oil temperature sensor 2h is provided in the oil pan 2g, but the oil temperature sensor 2h may be provided anywhere on the oil passage as long as it can measure the temperature of the oil. In this embodiment, the water temperature sensor 2f and the oil temperature sensor 2h are electrically connected to the engine control device 2a. However, the water temperature sensor 2f and the oil temperature sensor 2h may be electrically connected to the control device 20.

[0016] The internal combustion engine 2 drives the generator 4 via the transaxle 16. The internal combustion engine 2 is driven by the combustion of fuel supplied from a fuel tank (Fuel TANK) 23. Various devices and sensors of the internal combustion engine 2 are electrically connected to an engine control device (ENG-ECU) 2a. The engine control device 2a acquires a signal from the control device 20 and controls the internal combustion engine 2 to be in a desired operating state. The transaxle 16 amplifies the rotation speed of the internal combustion engine 2 and transmits it to the generator 4. The transaxle 16 of this embodiment also has a clutch 16a. The clutch 16a transmits and interrupts power between the internal combustion engine 2 and the front motor 6 and between the internal combustion engine 2 and the front wheel drive shaft 12a. The internal combustion engine 2 is connected to the front wheel drive shaft 12a via the clutch 16a of the transaxle 16 and drives the front wheel drive shaft 12a.

[0017] As shown in FIG. 1, the generator 4 is connected to the internal combustion engine 2 and generates electricity by being driven by the internal combustion engine 2. The electric power (first electric power) generated by the generator 4 can charge the drive battery 10 and can be supplied to each motor via the front inverter 18 and the rear inverter 8b. In this embodiment, the generator 4 is a motor generator, and in addition to generating electricity, it can crank or motor the internal combustion engine 2 by rotating and driving the internal combustion engine 2. When driven by the internal combustion engine 2, the generator 4 generates electricity by applying a load to the generator 4. On the other hand, the generator 4 is supplied with electric power from the drive battery 10 and powers the internal combustion engine 2 to crank or motor it. The generator 4 is controlled by a generator control device 4a provided in the front inverter 18. The generator control device 4a is electrically connected to the control device 20, receives a signal from the control device 20, and controls the power generation and power running so that the generator 4 is in a desired operating state.

[0018] The driving battery 10 is composed of secondary batteries such as lithium ion batteries, and has a battery module (not shown) configured with multiple battery cells. The driving battery 10 functions as a power source for each motor. The driving battery 10 also has a battery monitoring unit (BMU) 10a. The battery monitoring unit (BMU) 10a calculates the charging rate (State Of Charge, hereinafter referred to as SOC) of the battery module, and detects the deterioration state (State Of Health, hereinafter referred to as SOH) of the battery module, the voltage Bv of the battery module, and the battery temperature Btmp. The battery monitoring unit 10a obtains the voltage Bv, charging rate SOC, deterioration state SOH, and battery temperature Btmp of the driving battery 10, and transmits them to the control device 20.

[0019] The control device 20 executes at least the following controls: control for switching driving modes; power generation control for causing the internal combustion engine 2 to generate power in each driving mode; motoring control for driving the internal combustion engine 2 by the generator 4; and control for regenerative cooperative braking of the electric vehicle 1 using regenerative braking and friction braking.

[0020] In this embodiment, the control device 20 switches the driving mode to one of a series mode (series driving mode), a parallel mode (parallel driving mode), and an EV mode (EV driving mode) by controlling the clutch 16a based on information such as the speed V, the charging rate SOC, and the accelerator opening Th. In the parallel mode, the control device 20 connects the clutch 16a and drives the front wheel drive shaft 12a by both the internal combustion engine 2 and the front motor 6. At this time, the front motor 6 is supplied with either or both of electric power (second electric power) from the drive battery 10 and electric power (first electric power) generated by the generator 4. Similarly, the rear motor 8 is supplied with either or both of electric power (second electric power) from the drive battery 10 and electric power (first electric power) generated by the generator 4 to drive the rear wheel drive shaft 14a. In EV mode, the control device 20 releases the clutch 16a and supplies power (second power) from the drive battery 10 to each motor, which drives the front wheel drive shaft 12a and the rear wheel drive shaft 14a (hereinafter referred to as each drive shaft in the specification).

[0021] In the series mode, the control device 20 releases the clutch 16a, drives the generator 4 with the internal combustion engine 2, and supplies the first electric power generated by the generator 4 to each motor. If the first electric power is insufficient to provide the driving force for each motor to drive each drive shaft, the drive battery 10 also supplies the second electric power to each motor. Note that in the parallel mode and series mode, the drive battery 10 may be charged by supplying a portion of the electric power generated by the internal combustion engine 2 to the drive battery 10.

[0022] The control device 20 calculates a required power generation amount GEq as the amount of power generation that the generator 4 should generate in each of the driving modes of the parallel mode, the series mode, and the EV mode. The control device 20 applies a load to the generator 4 so that the required power generation amount GEq can be achieved. The control device 20 also calculates an engine required torque ETq, which is an output (torque) required of the internal combustion engine 2 so that the internal combustion engine 2 can drive the generator 4, and transmits the calculated torque to the engine control device 2a. The engine control device 2a obtains the engine required torque ETq and controls the internal combustion engine 2 so that the engine required torque ETq can be achieved. The control device 20 is actually configured by a microcomputer including a calculation device, a memory, an input / output buffer, and the like. The control device 20 controls each device so that the electric vehicle 1 is in a desired operating state based on signals from each sensor and various devices, and maps and programs stored in the memory. In this embodiment, the control device 20 executes torque-based control that calculates the torque that the internal combustion engine 2 and each motor should output based on a driver required torque DTq, which will be described later. Therefore, in the following specification, the meaning of output is the same as torque.

[0023] In this embodiment, various control devices including the engine control device 2a, the generator control device 4a, the front motor control device 6a, the rear motor control device 8a, and the battery monitoring unit 10a are provided separately from the control device 20. The various control devices are electrically connected to the control device 20. However, the various control devices may be provided integrally with the control device 20. Like the control device 20, the various control devices are configured by microcomputers including a calculation device, a memory, an input / output buffer, and the like.

[0024] The accelerator pedal 21 is a pedal that is depressed by the driver of the electric vehicle 1 to control acceleration and deceleration of the electric vehicle 1. The accelerator pedal 21 is provided with an accelerator position sensor 21a that detects the depression position. The accelerator position sensor 21a is electrically connected to the control device 20 and transmits the accelerator depression position (accelerator opening Th) to the control device 20. The control device 20 calculates a driver requested torque (an example of a driver requested output) DTq from the accelerator opening Th.

[0025] The external charging device 22 is a device that charges the driving battery 10 with electric power from a power source external to the electric vehicle 1 (hereinafter referred to as external charging in the specification). The external charging device 22 receives a supply of electric power, for example, from a charging facility external to the electric vehicle 1. The external charging device 22 converts the electric power supplied from the external power source into electric power suitable for charging the driving battery 10, and charges the driving battery 10.

[0026] Next, the control procedure of the control device 20 of this embodiment will be described with reference to the flowchart of Fig. 3 and the timing chart of Fig. 4. The control procedure described below may be executed by the engine control device 2a as well as the control device 20, but in this embodiment, the control procedure is executed by the control device 20. The control device 20 starts the control operation when an ignition switch (not shown) is turned on.

[0027] As shown in FIG. 3, in step S1, the control device 20 calculates an engine required torque ETq for operating the internal combustion engine 2, and prepares to start the internal combustion engine 2. The control device 20 starts the internal combustion engine 2 when it becomes necessary to generate electricity by the generator 4 in the series traveling mode, or when switching to the parallel traveling mode. After calculating the engine required torque ETq, the control device 20 calculates a torque (an example of a first output, hereinafter referred to as a water temperature estimated torque Tw) that is assumed to be output by the internal combustion engine 2 at the time of starting the internal combustion engine 2, based on the water temperature Wt detected by the water temperature sensor 2f. The start-up of the internal combustion engine 2 refers to a period during which the internal combustion engine 2 is motored (cranked). In other words, the start-up is a period from when the control device 20 executes firing to when the internal combustion engine 2 is started. In this embodiment, the control device 20 prestores a preset oil type (e.g., 0W20) for the internal combustion engine 2, and friction torque, which is the torque for friction resistance and pump loss that is expected to occur in the internal combustion engine 2 at the water temperature Wt when this set oil type is used. The control device 20 calculates the water temperature estimated torque Tw by adding the friction torque that may occur in the internal combustion engine 2 to the engine required torque ETq. The control device 20 calculates the target intake air amount Qt to be drawn into the cylinder of the internal combustion engine 2 and the fuel injection amount from this water temperature estimated torque Tw.

[0028] In addition, the control device 20 detects the shaft torque (one example of the second output, hereinafter referred to as actual torque Tr in the specification) of the output shaft of the internal combustion engine 2 driven by the generator 4 when the generator 4 motors (cranks) the internal combustion engine 2. Since the generator 4 drives the internal combustion engine 2 when motoring (cranking), the control device 20 can detect the actual torque Tr from the amount of electric power supplied to the generator 4. Therefore, the shaft torque of the internal combustion engine 2 detected by the generator 4 corresponds to the actual torque of the output shaft of the internal combustion engine 2. Note that since the generator 4 and the internal combustion engine 2 are connected via a shaft, the output and torque of the internal combustion engine 2 can be detected by the generator 4. Therefore, the output and torque of the internal combustion engine 2 can be calculated from the output and torque of the generator 4. That is, the output and torque of the internal combustion engine 2 can be converted into the output and torque of the generator 4. Therefore, the output and torque of the internal combustion engine 2 may be treated as substantially the same as the output and torque of the generator 4. Specifically, the following control may be executed using the output and torque of the generator 4 corresponding to the water temperature estimated torque Tw and the actual torque Tr used as the output (torque) of the internal combustion engine 2. As shown from time t0 to time t1 in Fig. 4, in step S1, the control device 20 starts calculating the water temperature estimated torque Tw and detecting the actual torque Tr, but motoring (cranking) of the internal combustion engine 2 has not started at this time. As shown in Fig. 3, when the control device 20 detects the water temperature estimated torque Tw and the actual torque Tr, the control device 20 advances the process to step S2.

[0029] In step S2, the control device 20 motors (cranks) the internal combustion engine 2 by the generator 4. As shown from time t1 to time t2 in Fig. 4, when the internal combustion engine 2 is motored (cranked), the engine speed of the internal combustion engine 2 increases. However, immediately after the internal combustion engine 2 is motored (cranked), both the water temperature estimated torque Tw and the actual torque Tr are not stable.

[0030] For this reason, the control device 20 judges whether motoring (cranking) is stable in step S3 as shown in FIG. 3. Here, the stable state of motoring (cranking) may be a state in which the fluctuation of the engine speed or engine output based on motoring (cranking) falls within a predetermined range. The control device 20 may judge that the above state has been reached and motoring (cranking) has stabilized when a predetermined time has elapsed since motoring (cranking) was started. The control device 20 may also detect a change in the actual torque Tr, and judge that motoring (cranking) has stabilized when the change in the actual torque Tr falls within a predetermined range. The control device 20 prohibits the execution of a first learning control, which will be described later, until motoring (cranking) is stabilized. When the control device 20 judges that motoring (cranking) is stable (step S3 YES), the process proceeds to step S4. If motoring (cranking) is not stable in step S3 (NO in step S3), the control device 20 returns the process to step S2 and continues motoring (cranking) of the internal combustion engine 2 until motoring (cranking) is stabilized.

[0031] In step S4, the control device 20 calculates the absolute value of the difference between the actual torque Tr and the water temperature estimated torque Tw, and judges whether the absolute value is equal to or greater than a predetermined torque (one example of a predetermined output) Td. In such an electric vehicle 1, the internal combustion engine 2 is stopped when the vehicle runs in EV mode or when the vehicle decelerates. For this reason, in such an electric vehicle 1, the internal combustion engine 2 is repeatedly started and restarted. As a result, when there is a discrepancy between the actual torque Tr and the water temperature estimated torque Tw, in addition to the case where the oil type is different from the set oil type, there are also cases where only the water temperature Wt rises and the oil temperature Ot does not rise. Therefore, in step S4, the control device 20 judges whether there is a discrepancy between the actual torque Tr and the water temperature estimated torque Tw, and uses the discrepancy in the calculation of the first learning control described later. The control device 20 calculates the absolute value of the difference between the actual torque Tr and the water temperature estimated torque Tw, and if the absolute value is greater than the predetermined torque Td (step S4 YES), the process proceeds to step S5.

[0032] In step S5, the control device 20 determines whether the absolute value of the difference between the water temperature Wt and the oil temperature Ot is within a predetermined temperature Dtmp. The oil temperature Ot takes a longer time to rise after the internal combustion engine 2 is started than the water temperature Wt. In particular, in an electric vehicle 1 in which the internal combustion engine 2 is repeatedly restarted, such a deviation between the oil temperature Ot and the water temperature Wt is likely to occur. Therefore, in step S5, the control device 20 determines whether there is a deviation between the oil temperature Ot and the water temperature Wt, and executes control according to the presence or absence of a deviation. If the control device 20 determines that the absolute value of the difference between the water temperature Wt and the oil temperature Ot is greater than the predetermined temperature Dtmp (step S5 NO), the process proceeds to step S6.

[0033] In step S6, the control device 20 starts the first learning control. From time t2 to time t3 in Fig. 4, the absolute value of the difference between the actual torque Tr and the water temperature estimated torque Tw during motoring (cranking) is calculated, and a graph is shown showing the values ​​of the actual torque Tr and the water temperature estimated torque Tw when the absolute value is greater than a predetermined torque Td. In the graph of Fig. 4, the water temperature estimated torque Tw is higher than the actual torque Tr. In other words, the graph of Fig. 4 shows a case where the actual friction torque is greater than the friction torque used for the water temperature estimated torque Tw.

[0034] When there is a deviation of a predetermined torque Td or more between the actual torque Tr and the water temperature estimated torque Tw, the control device 20 executes a first learning control for recording the differential torque between the actual torque Tr and the water temperature estimated torque Tw as a first learning value. The first learning control may record the differential torque between the actual torque Tr and the water temperature estimated torque Tw for a predetermined period (for example, between time t2 and time t3 in FIG. 4) after motoring (cranking) has stabilized, and calculate the average value of these as the first learning value. Alternatively, the differential torque between the actual torque Tr and the water temperature estimated torque Tw at time t3 or immediately before time t3 may be recorded as the first learning value.

[0035] Furthermore, the control device 20 may shorten the time (execution time) for executing the first learning control as the driver required torque DTq during motoring (cranking) becomes higher. The longer the learning time, the more accurate the learning can be. However, when the driver required torque DTq is high, there are cases where it is better to prioritize drivability over learning. In this way, the control device 20 may control to prioritize either the learning accuracy or drivability according to the driver required torque DTq. In any case, the control device 20 starts the first learning control during motoring (cranking) and records the first learning value. After starting the first learning control, the control device 20 proceeds to step S7.

[0036] In step S7, the control device 20 determines whether external charging is performed. If external charging is not performed (NO in step S7), the control device 20 proceeds to step S8. In step S8, the control device 20 acquires a first learned value. As described above, the first learned value is the differential torque between the actual torque Tr and the water temperature estimated torque Tw. After acquiring the first learned value, the control device 20 proceeds to step S9.

[0037] In step S9, the control device 20 corrects the target intake air amount Qt by reflecting the first learning value. Specifically, the control device 20 calculates a correction amount of the target intake air amount Qt to be supplied to the internal combustion engine 2 based on the differential torque. For example, when the water temperature estimated torque Tw is higher than the actual torque Tr, the friction torque is larger than expected. Therefore, the differential torque is a negative value. Therefore, the control device 20 executes correction control to increase the throttle opening ThO of the throttle valve 2b in order to increase the target intake air amount Qt. The control device 20 executes control to increase the fuel injection amount in accordance with the increase in the target intake air amount Qt. On the other hand, when the water temperature estimated torque Tw is lower than the actual torque Tr, the friction torque is smaller than expected. Therefore, the control device 20 executes control to reduce the target intake air amount Qt, reduce the throttle opening ThO, and reduce the fuel injection amount. After correcting the target intake air amount Qt reflecting the first learned value and correcting the opening degree of the throttle valve 2b, the control device 20 ignites the ignition plug 2i in step S10 to start firing.

[0038] As shown from time t3 to time t4 in FIG. 4, in this embodiment, firing and fuel injection are performed during this period. Specifically, fuel injection and firing are performed at time t3. In this embodiment, as shown in the change in the water temperature estimated torque Tw at time t3 in FIG. 4, when firing is performed at time t3, the combustion torque due to the intake air amount reflecting the first learning value is added. The control device 20 starts calculating the engine estimated torque Tw1 including the combustion torque reflecting the first learning value. Note that, in the period from time t3 to time t4, the control device 20 prohibits the execution of the first learning control in consideration of the influence of firing. When firing is performed, the control device 20 advances the process to step S11.

[0039] In step S11, the control device 20 determines that complete explosion has occurred. Complete explosion refers to a state in which the mixture in the cylinder of the internal combustion engine 2 has been ignited. In this embodiment, the control device 20 determines complete explosion by detecting whether the rotation of the internal combustion engine 2 has stabilized. However, the control device 20 may also determine complete explosion by whether the fluctuation of the actual torque Tr has decreased. If complete explosion has occurred, the control device 20 proceeds to the process of step S12.

[0040] In step S12, the control device 20 executes a second learning control to learn the intake air amount based on the difference between the engine estimated torque Tw1 (an example of a third output) of the internal combustion engine 2 reflecting the first learning value and the actual torque Tr after the internal combustion engine 2 has completely exploded. At this time, the control device 20 detects the actual torque Tr based on the power generation amount of the generator 4. As shown after time t4 in FIG. 4, the control device 20 stabilizes the operation of the internal combustion engine 2 while maintaining the internal combustion engine 2 at a predetermined rotation speed and a predetermined load after the internal combustion engine 2 has completely exploded. In this embodiment, the control device 20 maintains the engine at a predetermined rotation speed while keeping the engine required torque ETq constant, and applies a predetermined load to the generator 4 to generate power. At this time, the oil temperature Ot rises and approaches the water temperature Wt.

[0041] As shown after time t4 in FIG. 4, the control device 20 records a second learning value based on the difference between the engine estimated torque Tw1 and the actual torque Tr (see X in FIG. 4). As shown in the graph of the second learning value in FIG. 4, the control device 20 records the second learning value in real time and corrects the target intake air amount Qt and the throttle opening ThO in real time. This corrects the reduction in friction torque that corresponds to the increase in oil temperature Ot. As a result, the actual torque Tr (the exerted output) can be quickly matched to the engine required torque ETq. After executing the second learning control, the control device 20 returns the process to step S1 and performs the same control procedure the next time the internal combustion engine 2 is restarted.

[0042] In step S4, the control device 20 calculates the absolute value of the difference between the actual torque Tr and the water temperature estimated torque Tw, and if it determines that the absolute value is smaller than the predetermined torque Td (NO in step S4), the process proceeds to step S13, where firing is performed, and then the process proceeds to step S11. If the absolute value of the difference between the actual torque Tr and the water temperature estimated torque Tw is smaller than the predetermined torque Td, the influence of the deviation between the water temperature Wt and the oil temperature Ot on the start of the internal combustion engine 2 is small. Therefore, in step S11, the control device 20 does not execute the first learning control, and promptly starts the internal combustion engine 2 by full combustion.

[0043] In step S5, when the control device 20 determines that the absolute value of the difference between the water temperature Wt and the oil temperature Ot is smaller than the predetermined temperature (step S5 YES), the control device 20 proceeds to step S14 and determines that an oil type different from the setting has been put into the internal combustion engine 2. If there is no deviation between the water temperature Wt and the oil temperature Ot, the water temperature estimated torque Tw should be close to the actual torque Tr. However, if there is no deviation between the water temperature Wt and the oil temperature Ot but the difference between the actual torque Tr and the water temperature estimated torque Tw is equal to or larger than a predetermined value, it is considered that an oil type with a different viscosity than that used in the calculation of the water temperature estimated torque Tw has been used. Therefore, the control device 20 executes such a control procedure to quickly determine the difference from the set oil type. In this case, when the control device 20 determines that the oil type is incorrect in step S14, the process proceeds to step S15, where the control device 20 quickly obtains the difference between the actual torque Tr and the water temperature estimated torque Tw, and executes the correction calculation of the target intake air amount Qt and the correction of the throttle opening ThO of the throttle valve 2b. In other words, the control device 20 obtains the difference between the water temperature estimated torque Tw and the actual torque Tr without executing the first learning control. Then, the control device 20 proceeds to step S16 from step S15, executes firing, and proceeds to step S11. This allows the actual torque Tr (the exerted output) to be quickly matched to the engine required torque ETq (the target output). In addition, since the first learning control is not executed, the calculation load of the control device 20 is also reduced.

[0044] In step S7, if the control device 20 determines that external charging is occurring (step S7 YES), the process proceeds to step S17, where the control device 20 changes the time of the first learning control. Specifically, the control device 20 lengthens the time of the first learning control. When external charging is occurring, the charging rate SOC of the driving battery 10 is high. For this reason, the motoring (cranking) time can be made longer, and accordingly, the time of the first learning control can easily be made longer. This makes it easier to improve the accuracy of the first learned value. As a result, it is easier to quickly achieve the target output after the internal combustion engine 2 starts, while suppressing starting failures.

[0045] As described above, according to the present disclosure, it is possible to provide a control device 20 for an electric vehicle 1 that is likely to produce a target output quickly after the internal combustion engine 2 has started.

[0046] <Other embodiments> Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0047] (a) In the above embodiment, a four-wheel drive plug-in hybrid vehicle has been described as an example, but the present disclosure is not limited thereto. The electric vehicle 1 may be a front-wheel drive hybrid vehicle or a plug-in hybrid vehicle. The electric vehicle 1 may also be a four-wheel drive hybrid vehicle.

[0048] (b) In the above embodiment, an example has been described in which the control device 20 executes all of the control procedures, but the present disclosure is not limited to this. A part of the control procedures of the control device 20 may be executed by the engine control device 2a. [Explanation of symbols]

[0049] 1: Electric vehicles 2: Internal combustion engine 2b: Throttle valve 2f: Water temperature sensor (an example of a water temperature detection unit) 2h: Oil temperature sensor (an example of an oil temperature detector) 4: Generator (first rotating electric machine) 20: Control device 22: External charging device Ot:Oil temperature Wt:Water temperature

Claims

1. A control device for an electric vehicle having an internal combustion engine including a throttle valve and a first rotating electric machine capable of driving the internal combustion engine, execute a first learning control for learning an intake air amount at the start of the internal combustion engine based on a difference between a first output calculated as an output at the start of the internal combustion engine, which is a period until firing for starting the internal combustion engine is performed, which is estimated based on a water temperature of the internal combustion engine, and a second output which is an output of the internal combustion engine driven by the first rotating electric machine at the start of the internal combustion engine, when the first rotating electric machine drives the internal combustion engine to motor it; controlling the throttle valve so as to obtain the intake air amount learned by the first learning control, and then performing fuel injection and firing for starting the internal combustion engine. A control device for an electric vehicle.

2. After the fluctuation in the engine speed or the engine output based on the motoring falls within a predetermined range, the first learning control is executed. The control device for an electric vehicle according to claim 1.

3. After the internal combustion engine has completely exploded, a second learning control is executed to learn the intake air amount based on a difference between a third output, in which a first learning value, which is a difference between the first output and the second output, is reflected in the first output, and the second output. The control device for an electric vehicle according to claim 1 or 2.

4. The internal combustion engine includes a water temperature detection unit that detects a water temperature of the internal combustion engine, and an oil temperature detection unit that detects an oil temperature of the internal combustion engine, the control device for the electric vehicle determines that the type of oil input to the internal combustion engine is different from the type of oil used in calculating the first output when the difference between the first output and the second output is equal to or greater than a predetermined output and the difference between the water temperature and the oil temperature is smaller than a predetermined temperature. The control device for an electric vehicle according to any one of claims 1 to 3.

5. When it is determined that the oil types are different, the intake air amount is corrected based on a difference between the first output and the second output at the time of the determination. The control device for an electric vehicle according to claim 4.

6. the electric vehicle has a drive battery and an external charging device that charges the drive battery from an external power supply of the electric vehicle, the control device for the electric vehicle extends an execution time of the first learning control when the driving battery is charged from the external power supply. The control device for an electric vehicle according to any one of claims 1 to 5.

7. the execution time of the first learning control is shortened as the driver required output required for the electric vehicle when the first rotating electric machine drives the internal combustion engine is higher. The control device for an electric vehicle according to any one of claims 1 to 6.

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