JP7706487B2 - Hybrid vehicle control device - Google Patents

Description

The present invention relates to a control device for a hybrid vehicle.

One example of a system that is installed in a hybrid vehicle equipped with multiple power sources is the so-called series hybrid system. A series hybrid system includes, for example, an engine, a generator motor that generates electricity using engine power, a drive motor that generates driving force for traveling, and a battery that stores the electricity supplied to the drive motor and the like. Hereinafter, a hybrid vehicle equipped with such a series hybrid system will be referred to simply as a "hybrid vehicle." Furthermore, the power output will also be referred to simply as "power" or "output."

Hybrid vehicles run in either EV (Electric Vehicle) mode or HV (Hybrid Vehicle) mode. In EV mode, the vehicle runs only on electricity supplied from a battery, without any power generation from a generator motor. In HV mode, the vehicle runs on both electricity generated by a generator motor using engine power and electricity supplied from a battery.

If the battery output during EV driving becomes less than the required power, the engine is started and the vehicle switches to HV driving. The required power is, for example, the sum of the power required for driving, the power required to start the engine, margins, losses (various energy losses), electrical load, etc.

The driving patterns of a hybrid vehicle are roughly classified into the following three types (1) to (3).
(1) "Required power < battery output": EV driving (engine stopped)
(2) "Required power > battery output" and "before engine start is complete": HV driving (driving with power obtained by subtracting "power required to start the engine" from "battery output")
(3) "Required power > battery output" and "After engine start is complete": HV driving (driving with the sum of "battery output" and "power generated by engine operation")

International Publication No. 2014-038350

In addition, in a hybrid vehicle, there are cases where the vehicle attempts to accelerate from a state in which the engine is operating in F/C (fuel cut: fuel supply is stopped) (engine F/C operating state). An example of a situation in which the engine enters the F/C operating state is when the battery is fully charged and the generator motor is operated to consume power.

When attempting to accelerate from an engine F/C operating state in a hybrid vehicle, unnecessary acceleration/deceleration (acceleration or deceleration) may occur in the hybrid vehicle due to, for example, the magnitude relationship between the actual engine speed and the target engine speed (calculated from the required driving force) or differences in the responsiveness (response speed) of the engine and the generator motor (details will be described later). In other words, smooth acceleration may not be achieved.

The present invention has been made in consideration of the above circumstances, and aims to provide a control device for a hybrid vehicle that can achieve smooth acceleration when accelerating from an engine F/C operating state in a series hybrid vehicle.

In order to solve the above-mentioned problems, the control device for a hybrid vehicle of the present invention includes an internal combustion engine that runs on fuel, a generator motor that can convert the power of the internal combustion engine into electric power when the internal combustion engine is operating and can start the internal combustion engine using electric power from a battery when the internal combustion engine is not operating, a drive motor that uses electric power to supply driving force to the drive wheels for running, and the battery that can output electric power to the generator motor and the drive motor. In a start control that supplies fuel to the internal combustion engine to start the internal combustion engine when there is a request to accelerate the hybrid vehicle from a motoring state in which the generator motor is powered to rotate the internal combustion engine while stopping the supply of fuel to the internal combustion engine, the target rotation speed of the internal combustion engine is calculated from the required driving force, and if the actual rotation speed of the internal combustion engine is lower than the target rotation speed, the rotation speed of the internal combustion engine is maintained within a predetermined time after the start of fuel supply to the internal combustion engine.

According to the above configuration, when the internal combustion engine accelerates from a state in which it is operating in F/C, at least when the above conditions are met, the rotation speed of the internal combustion engine is maintained for the specified time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle and achieving smooth acceleration.

In addition, in the control device for the hybrid vehicle, the internal combustion engine's target rotation speed is calculated from the driving force corresponding to the accelerator opening according to the amount of accelerator pedal operation by the driver, and if the actual rotation speed of the internal combustion engine is greater than the target rotation speed, the internal combustion engine's rotation speed is maintained within the specified time if the actual rotation speed is greater than the target rotation speed.

According to the above configuration, when the above conditions are met based on the amount of accelerator pedal operation by the driver, the rotation speed of the internal combustion engine is maintained within the specified time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle and achieving smooth acceleration.

In addition, in the control device for the hybrid vehicle, when the reached rotation speed of the internal combustion engine is lower than the actual rotation speed and the reached rotation speed is higher than the target rotation speed, the rotation speed of the internal combustion engine is maintained within the predetermined time.

According to the above configuration, if the above conditions are met, the rotation speed of the internal combustion engine is maintained within the specified time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle and achieving smooth acceleration.

According to the present invention, when the internal combustion engine accelerates from a state in which it is operating in F/C, if a predetermined condition is satisfied, the rotation speed of the internal combustion engine is maintained within the predetermined time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle and achieving smooth acceleration.

FIG. 1 is a diagram showing an example of a main configuration of a hybrid vehicle according to an embodiment. FIG. 2 is a graph showing the change over time of each parameter before the change (conventional technology) and after the change (embodiment) in the first control outline example. FIG. 3 is a graph showing the change over time of each parameter before the change (prior art) and after the change (embodiment) in the second control outline example. FIG. 4 is a flow chart showing the process before (prior art) and after (embodiment) the modification. FIG. 5 is an explanatory diagram of a first control example in the embodiment. FIG. 6 is an explanatory diagram of a second control example in the embodiment. FIG. 7 is an explanatory diagram of a third control example in the embodiment.

Below, an embodiment of a control device for a hybrid vehicle of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiment. In addition, in the graphs of Figures 2, 3, and 5 to 7, the vertical relationship of the parts where multiple lines are close to each other does not necessarily match the magnitude relationship of the actual numerical values due to the convenience of drawing.

Figure 1 is a diagram showing an example of the main configuration of a hybrid vehicle 1 according to an embodiment. The main configuration of the hybrid vehicle 1 according to this embodiment will be described with reference to Figure 1.

The hybrid vehicle 1 is a vehicle equipped with a series hybrid system 2. The hybrid vehicle 1 includes drive wheels 17, an ECU (Electronic Control Unit) 31, an accelerator sensor 32, a brake switch 33, and a vehicle speed sensor 34.

The hybrid system 2 also includes an engine 11, a generator motor 12 (MG1: generator motor), a drive motor 13 (MG2: drive motor), a battery 14, and a PCU (Power Control Unit) 15.

The engine 11 is, for example, an internal combustion engine such as a gasoline engine.

The generator motor 12 can convert the power of the engine 11 into electricity when the engine 11 is operating, and can start the engine 11 using electricity from the battery 14 when the engine 11 is not operating.

The drive motor 13 uses power from the battery 14 to supply the drive force to the drive wheels 17 for running.

The battery 14 is configured to output power to the generator motor 12 and the drive motor 13.

The PCU 15 is a unit for controlling the driving of the generator motor 12 and the drive motor 13. The PCU 15 includes a first inverter 21, a second inverter 22, and a converter 23.

The first inverter 21 is an inverter device that converts DC power from the converter 23 into AC power and converts AC power generated by the generator motor 12 into DC power.

The second inverter 22 is an inverter device that converts DC power from the converter 23 into AC power and converts AC power generated by regenerative operation of the drive motor 13 into DC power.

The converter 23 is a converter device that boosts the DC power output from the battery 14 or reduces the DC power output from the first inverter 21 or the second inverter 22.

When the hybrid vehicle 1 is running, the drive motor 13 is powered and generates power.

When the hybrid vehicle 1 is running and the output required for the drive motor 13 is smaller than the output of the battery 14, the hybrid vehicle 1 runs in EV (Electric Vehicle) mode. That is, in EV mode, the engine 11 is stopped, no power is generated by the generator motor 12, and the drive motor 13 is driven only by the power supplied from the battery 14 via the converter 23 and the second inverter 22.

On the other hand, when the output required of the drive motor 13 exceeds the output of the battery 14 while the hybrid vehicle 1 is running, the hybrid vehicle 1 runs in HV (Hybrid Vehicle) mode. In other words, during HV running, the drive motor 13 is driven by both the power generated by the generator motor 12 and the power supplied from the battery 14.

The ECU 31 is a control device that controls the hybrid system 2. The hybrid vehicle 1 is equipped with multiple ECUs including the ECU 31. Each ECU has a microcontroller unit (microcomputer). The microcomputer has built-in, for example, a central processing unit (CPU), a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM). The multiple ECUs are interconnected to enable two-way communication using the controller area network (CAN) communication protocol. Each ECU is connected to various sensors required for control, and receives detection signals from the connected sensors. In addition to the detection signals input from the various sensors, each ECU also receives information required for control from other ECUs.

In such a hybrid vehicle 1, there are cases where the engine 11 attempts to accelerate from a state in which it is operating at F/C. In such cases, for example, unnecessary acceleration or deceleration may occur in the hybrid vehicle 1 due to the magnitude relationship between the actual engine speed and the target engine speed, differences in responsiveness between the engine and the generator motor, and the like. In other words, smooth acceleration may not be achieved.

Therefore, below, we will explain a technology that can achieve smooth acceleration when accelerating from a state in which the engine 11 is operating in F/C.

First, the control outline of the conventional technology and this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a graph showing the time-dependent changes in each parameter before the change (conventional technology) and after the change (embodiment) in the first control outline example. In the following, "common" means "common to the conventional technology and embodiment."

Symbols G11 to G14 indicate the rotation speed of the engine 11.
Reference symbol G11 denotes a common target rotation speed (a target value of the rotation speed at each moment) and is calculated from the required driving force.

Reference symbol G12 denotes the actual rotation speed in the prior art.
Reference symbol G13 denotes a target rotation speed in the embodiment. The target rotation speed is a rotation speed that is ultimately desired to be realized and is calculated based on the amount of accelerator pedal operation by the driver.
Reference symbol G14 denotes the actual rotation speed in this embodiment.

Reference symbol G15 is the actual torque of the generator motor 12 in the prior art.
Reference symbol G16 is the actual torque of the generator motor 12 according to the embodiment.

Symbol G17 is the common actual torque of engine 11.

Symbols G18 to G21 indicate the torque of the drive motor 13.
Reference symbol G18 is the target torque in the prior art.
Reference symbol G19 is the actual torque in the prior art.

Reference symbol G20 denotes a target torque in this embodiment.
Reference symbol G21 denotes the actual torque in this embodiment.

In this example, when attempting to accelerate the hybrid vehicle 1 from a state in which the engine 11 is operating at F/C, in the prior art, the actual rotation speed (symbol G12) of the engine 11 is initially greater than the target rotation speed (symbol G11), so the target rotation speed (symbol G11) calculated from the required driving force drops once in time period T1 and then rises in time period T2. As a result, the actual torque (symbol G15) of the generator motor 12 drops once in time period T1 and then rises in time period T2.

As a result, the actual torque (symbol G19) of the drive motor 13 increases toward acceleration in time period T1, and then decreases toward deceleration in time period T2. Therefore, smooth acceleration cannot be achieved, and, for example, a shock (sudden acceleration or deceleration of the hybrid vehicle 1) occurs.

On the other hand, in the embodiment, under certain conditions (described in detail later), the actual rotation speed (symbol G14) of the engine 11 is held (maintained) during time periods T1 and T2. As a result, the actual torque (symbol G16) of the generator motor 12 becomes constant during time periods T1 and T2. As a result, the actual torque (symbol G21) of the drive motor 13 becomes constant during time periods T1 and T2, realizing smooth acceleration without shock.

Next, FIG. 3 is a graph showing the time course of each parameter before the change (conventional technology) and after the change (embodiment) in the second control overview example. Symbols G31 to G41 are the same as symbols G11 to G21 in FIG. 2.

In this example, when attempting to accelerate the hybrid vehicle 1 from a state in which the engine 11 is operating at F/C, in the prior art, the target rotation speed (symbol G31) and actual rotation speed (symbol G32) of the engine 11 initially rise in time period T31. However, since the response of the generator motor 12 is generally faster than the response of the engine 11, the actual torque (symbol G35) of the generator motor 12 rises in time period T3.

As a result, the actual torque of the drive motor 13 (symbol G39) decreases toward the deceleration side during time period T3. This makes it impossible to achieve smooth acceleration, and shocks, for example, occur.

On the other hand, in the embodiment, under certain conditions (described in detail later), the actual rotation speed (symbol G34) of the engine 11 is held (maintained) during time period T3. As a result, the actual torque (symbol G36) of the generator motor 12 becomes constant during time period T3. As a result, the actual torque (symbol G41) of the drive motor 13 becomes constant during time period T3, realizing smooth acceleration without generating shock.

The following is a detailed explanation with reference to Figures 4 to 7. Figure 4 is a flow chart showing the process (a) before the change (conventional technology) and (b) after the change (embodiment).

As shown in FIG. 4A, in the process before the change (prior art), first, in step S101, the engine 11 is operating at F/C (motoring state).
Next, in step S102, the ECU 31 detects the driver's depression of the accelerator pedal for accelerating the hybrid vehicle 1.

Next, in step S103, the ECU 31 calculates the target rotation speed of the engine 11 from the required driving force.

Next, in step S104, the ECU 31 executes FF (feedforward) control of the engine 11 toward the target rotation speed.

However, as explained in Figures 2 and 3, this type of processing may not achieve smooth acceleration. Therefore, in this embodiment, the processing shown in Figure 4(b) is performed.

Steps S1 and S2 in FIG. 4(b) are similar to steps S101 and S102 in FIG. 4(a).

Next, in step S3, the ECU 31 calculates the target rotation speed of the engine 11 from the required driving force, and calculates the attained rotation speed of the engine 11 from the driving force corresponding to the accelerator opening according to the amount of accelerator pedal operation by the driver.

Next, in step S4, the ECU 31 determines whether the actual rotation speed of the engine 11 is greater than the target rotation speed, and if Yes, proceeds to step S5, and if No, proceeds to step S10.

In step S5, the ECU 31 determines whether the reached rotation speed of the engine 11 is greater than the actual rotation speed, and if Yes, proceeds to step S6, and if No, proceeds to step S7.

In step S6, the ECU 31 holds (maintains) the actual rotation speed of the engine 11.

In step S7, the ECU 31 determines whether the reached rotation speed of the engine 11 is greater than the target rotation speed, and if Yes, proceeds to step S8, and if No, proceeds to step S9.

In step S8, the ECU 31 holds (maintains) the actual rotation speed of the engine 11.

In step S9, the ECU 31 executes FF control of the engine 11 toward the target rotation speed.

In step S10, the ECU 31 determines whether the time that has elapsed since returning from F/C is within a predetermined time. If Yes, the process proceeds to step S11. If No, the process proceeds to step S12. The predetermined time is set according to the difference in responsiveness between the generator motor 12 and the engine 11, so that when accelerating the hybrid vehicle 1 from the engine F/C operating state, the start timing of the increase in engine speed of the generator motor 12 to the rise in the actual torque of the engine 11 is matched to the rise in the engine speed.

In step S11, the ECU 31 holds (maintains) the actual rotation speed of the engine 11.

In step S12, the ECU 31 executes FF control of the engine 11 toward the target rotation speed.

Next, the first to third control examples will be described with reference to Figs. 5 to 7. Fig. 5 is an explanatory diagram of the first control example in the embodiment. Fig. 5 is based on the premise that immediately after the accelerator pedal is operated, there is a magnitude relationship for the engine 11, that is, actual rotation speed < target rotation speed < achieved rotation speed. Fig. 5(a) is the same as Fig. 4(b).

FIG. 5B shows an example of control before the change (prior art).
Reference characters G51 to G53 indicate the rotation speed of the engine 11.
Reference symbol G51 is the target rotation speed.
Reference symbol G52 is the actual rotation speed.
Reference symbol G53 is the final rotation speed.

Reference symbol G54 is the actual torque of the generator motor 12.
Reference symbol G55 is the actual torque of the engine 11.

At time t51, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G53) increases sharply, the target rotation speed of the engine 11 (symbol G51) increases, and the actual rotation speed of the engine 11 (symbol G52) increases following the target rotation speed (symbol G51).

The actual torque of the generator motor 12 (G54) rises once after time t51 (see FIG. 3). Then, the actual torque of the engine 11 (G55), which has a lower responsiveness (slower response speed) than the generator motor 12, rises from time t52.

Among the above, one of the reasons why the hybrid vehicle 1 cannot achieve smooth acceleration is that the actual torque (symbol G54) of the generator motor 12 increases once after time t51.

On the other hand, FIG. 5(c) is an example of control after the change (embodiment). References G61 to G65 are the same as references G51 to G55. Explanations of matters similar to those in FIG. 5(b) will be omitted as appropriate.

At time t61, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G63) rises sharply, and the target rotation speed of the engine 11 (symbol G61) rises, but the actual rotation speed of the engine 11 (symbol G62) does not change until time t62. Therefore, from time t61 to t62, the process of symbol D (step S11) is executed. Explaining this with reference to the flowchart in FIG. 5(a), the answer is No in step S4, the answer is Yes in step S10, and the actual rotation speed of the engine 11 is maintained in step S11.

The actual rotation speed of the engine 11 (symbol G62) also increases from time t62 (symbol E). Explaining this with reference to the flowchart in FIG. 5(a), the answer is No in step S10, and in step S12, FF control is executed for the engine 11 toward the target rotation speed.

Then, after time t61, the actual torque of the generator motor 12 (symbol G64) does not change until time t62, and then starts to decrease from time t62.

In addition, the actual torque of the engine 11 (symbol G65) begins to increase from time t62, which is a predetermined time (symbol T4) after time t61.

In this way, smooth acceleration of the hybrid vehicle 1 can be achieved. To achieve this, the ECU 31 calculates the target rotation speed of the engine 11 from the required driving force during start control, in which fuel is supplied to the engine 11 and started by supplying fuel to the engine 11 in response to a request for acceleration of the hybrid vehicle from a motoring state in which the generator motor 12 is powered to rotate the engine 11 while fuel supply to the engine 11 is stopped, and the ECU 31 maintains the rotation speed of the engine 11 if the actual rotation speed of the engine 11 is lower than the target rotation speed within a predetermined time after fuel supply to the engine 11 begins.

Next, FIG. 6 is an explanatory diagram of a second control example in the embodiment. In FIG. 6, it is assumed that immediately after the accelerator pedal is operated, there is a magnitude relationship for the engine 11, that is, target rotation speed < actual rotation speed < achieved rotation speed. Explanations of matters similar to those in FIG. 5 will be omitted as appropriate.

Figure 6(b) shows an example of control before the change (prior art). Symbols G71 to G75 are the same as symbols G51 to G55 in Figure 5(b).

At time t71, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G73) rises sharply, the target rotation speed of the engine 11 (symbol G71) drops once and then rises, and the actual rotation speed of the engine 11 (symbol G72) drops once and then rises following the target rotation speed (symbol G71).

Furthermore, the actual torque of the generator motor 12 (symbol G74) drops once after time t71 and then rises once. Furthermore, the actual torque of the engine 11 rises from time t72.

Among the above, one of the reasons why the hybrid vehicle 1 cannot achieve smooth acceleration is that the actual torque of the generator motor 12 (symbol G74) drops once after time t71 and then rises once.

On the other hand, FIG. 6(c) is an example of control after the change (embodiment). References G81 to G85 are the same as references G71 to G75. Explanations of matters similar to those in FIG. 6(b) will be omitted as appropriate.

At time t81, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G83) rises sharply, and the target rotation speed of the engine 11 (symbol G81) drops once and then rises once, but the actual rotation speed of the engine 11 (symbol G82) does not change until time t82. Therefore, from time t81 to t82, the processes (symbol A (step S6), symbol D (step S11)) are executed.

This is explained using the flowchart in FIG. 6(a). In the process leading to symbol A (step S6), the answer is Yes in step S4, the answer is Yes in step S5, and the actual rotation speed of the engine 11 is held in step S6. In the process leading to symbol D (step S11), the answer is No in step S4, the answer is Yes in step S10, and the actual rotation speed of the engine 11 is held in step S11.

In addition, the actual rotation speed of the engine 11 (symbol G82) increases from time t82 (symbol E) (similar to FIG. 5).

Then, after time t81, the actual torque of the generator motor 12 (symbol G84) does not change until time t82, and then starts to decrease.

In addition, the actual torque of the engine 11 (symbol G85) begins to increase from time t82, which is a predetermined time (symbol T4) after time t81.

In this way, smooth acceleration of the hybrid vehicle 1 can be achieved. To achieve this, the ECU 31 calculates the target rotation speed of the engine 11 from the driving force corresponding to the accelerator opening according to the amount of accelerator pedal operation by the driver, and if the actual rotation speed of the engine 11 is higher than the target rotation speed (Yes in step S4) and the target rotation speed is higher than the actual rotation speed (Yes in step S5), the ECU 31 maintains the rotation speed of the engine 11 for a predetermined period of time (symbol A (step S6)).

Next, FIG. 7 is an explanatory diagram of a third control example in the embodiment. In FIG. 7, it is assumed that immediately after the accelerator pedal is operated, there is a magnitude relationship for the engine 11, that is, target rotation speed < actual rotation speed < achieved rotation speed. Explanations of matters similar to at least one of FIG. 5 and FIG. 6 will be omitted as appropriate.

Figure 7(b) shows an example of control before the change (prior art). Symbols G91 to G95 are the same as symbols G51 to G55 in Figure 5(b).

At time t91, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G93) decreases, the target rotation speed of the engine 11 (symbol G91) decreases once and then increases, and the actual rotation speed of the engine 11 (symbol G92) decreases once and then increases following the target rotation speed (symbol G91).

Furthermore, the actual torque of the generator motor 12 (symbol G94) drops once after time t91 and then rises once. Furthermore, the actual torque of the engine 11 rises from time t92.

Among the above, one of the reasons why the hybrid vehicle 1 cannot achieve smooth acceleration is that the actual torque of the generator motor 12 (symbol G94) drops once after time t91 and then rises once.

On the other hand, FIG. 7(c) is an example of control after the change (embodiment). References G101 to G105 are the same as references G91 to G95. Explanations of matters similar to those in FIG. 7(b) will be omitted as appropriate.

At time t101, the driver's depression of the accelerator pedal to accelerate the hybrid vehicle 1 is detected. After that, the target rotation speed of the engine 11 (symbol G103) decreases, and the target rotation speed of the engine 11 (symbol G101) decreases and then increases. However, the actual rotation speed of the engine 11 (symbol G102) does not change until time t102, except for changing to follow the target rotation speed (symbol G103). Therefore, from time t101 to t102, the processes of symbols A (step S6), B (step S8), and D (step S11) are executed.

This is explained using the flowchart in Figure 7 (a). In the process leading to symbol A (step S6), the answer is Yes in step S4, then Yes in step S5, and the actual rotation speed of the engine 11 is held in step S6. In the process leading to symbol B (step S8), the answer is Yes in step S4, then No in step S5, then Yes in step S7, and the actual rotation speed of the engine 11 is held in step S8. In addition, in the process leading to symbol D (step S11), the answer is No in step S4, then Yes in step S10, and the actual rotation speed of the engine 11 is held in step S11.

In addition, the actual torque (symbol G104) of the generator motor 12 does not change after time t101 until time t102, except for changes in response to changes in the actual rotation speed (symbol G102) of the engine 11 to follow the target rotation speed (symbol G103), and then decreases from time t102.

In addition, the actual torque of the engine 11 (symbol G105) begins to increase from time t102, which is a predetermined time (symbol T4) after time t101.

In this way, smooth acceleration of the hybrid vehicle 1 can be achieved. To this end, when the reached rotation speed of the engine 11 is lower than the actual rotation speed and the reached rotation speed is higher than the target rotation speed, the ECU 31 maintains the rotation speed of the engine 11 within the predetermined time.

In this way, according to the control device for the hybrid vehicle 1 of this embodiment, when the engine 11 accelerates from a state in which it is operating at F/C, if a certain condition is satisfied, the engine 11 speed is maintained within the specified time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle 1 and achieving smooth acceleration. Therefore, it is possible to suppress vibrations and noise in the hybrid vehicle 1 and improve the ride comfort for the occupants.

In addition, based on the amount of accelerator pedal operation by the driver, if certain conditions are met, the engine 11 speed is maintained for the specified period of time, thereby avoiding unnecessary acceleration and deceleration in the hybrid vehicle and achieving smooth acceleration.

In addition, by avoiding unnecessary increases in the actual torque of the generator motor 12 within the specified time, power can be saved and the saved power can be used to accelerate the hybrid vehicle 1.

The program executed by the ECU 31 of this embodiment can be provided by recording it in an installable or executable file format on a recording medium that can be read by a computer device, such as a CD (Compact Disc)-ROM (Read Only Memory), a flexible disk (FD), a CD-R (Recordable), or a DVD (Digital Versatile Disk). The program can also be provided or distributed via a network such as the Internet.

Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This new embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1...Hybrid vehicle, 11...Engine, 12...Generator motor, 13...Drive motor, 14...Battery, 15...PCU, 16...Drive system, 17...Drive wheels, 21...First inverter, 22...Second inverter, 23...Converter, 31...ECU, 32...Accelerator sensor, 33...Brake switch, 34...Vehicle speed sensor

Claims (2)

A control device for a hybrid vehicle including an internal combustion engine that runs on fuel, a generator motor that can convert the motive power of the internal combustion engine into electric power when the internal combustion engine is in operation and can start the internal combustion engine using electric power from a battery when the internal combustion engine is not in operation, a drive motor that uses electric power to supply drive force to drive wheels for traveling, and the battery that can output electric power to the generator motor and the drive motor,
In a start control in which, upon a request for acceleration of the hybrid vehicle from a motoring state in which the internal combustion engine is rotated by powering the generator motor while stopping the supply of fuel to the internal combustion engine, fuel is supplied to the internal combustion engine to start it, a target rotation speed of the internal combustion engine is calculated from a required driving force, and if the actual rotation speed of the internal combustion engine is lower than the target rotation speed, the actual rotation speed of the internal combustion engine is maintained within a predetermined time after the start of the supply of fuel to the internal combustion engine, and at that time,
A control device for a hybrid vehicle, which calculates an attainable rotation speed of the internal combustion engine from a driving force corresponding to an accelerator opening according to an amount of accelerator pedal operation by a driver, and when the actual rotation speed of the internal combustion engine is higher than the target rotation speed and the attained rotation speed is higher than the actual rotation speed, maintains the actual rotation speed of the internal combustion engine within the specified time . 2. The control device for a hybrid vehicle according to claim 1, wherein when the attained rotation speed of the internal combustion engine is lower than the actual rotation speed and the attained rotation speed is higher than the target rotation speed, the actual rotation speed of the internal combustion engine is maintained within the predetermined time.

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