JP2002021601A - Engine operation control device for hybrid electric vehicle - Google Patents

Abstract

(57) Abstract: The present invention relates to an engine operation control device for a hybrid electric vehicle, which eliminates and reduces an uncomfortable feeling of an engine rotation feeling with respect to an accelerator operation,
It is possible to prevent a decrease in battery voltage when the accelerator is quickly depressed. When the accelerator pedal depression amount is detected by an accelerator pedal depression amount detector, an accelerator pedal depression speed calculator calculates the accelerator pedal depression speed based on the detected information. And
The target throttle opening change rate setting means 62 sets the change rate of the target throttle opening of the engine during power generation according to the accelerator depression speed. As a result, when the accelerator is quickly depressed, the engine rotation speed increases quickly, and it is possible to eliminate a sense of discomfort due to the accelerator operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an engine operation control device suitable for use in a series hybrid electric vehicle.

[0002]

2. Description of the Related Art Hitherto, a hybrid electric vehicle in which an internal combustion engine (engine) and an electric motor (motor) are combined to obtain a driving force of a vehicle has been developed and put into practical use. Such hybrid electric vehicles include a series hybrid electric vehicle using an engine exclusively as a power supply source for a motor and a parallel hybrid electric vehicle in which both an output shaft of an engine and an output shaft of a motor are mechanically connected to drive wheels. Electric vehicles are known.

[0003] Among them, in a series hybrid electric vehicle, a motor is operated by power supply from a battery to run the vehicle. When the remaining power of the battery is less than a first predetermined value (for example, 60%), the engine is operated to drive the generator, charge the battery, and supply power to the motor. In addition, the remaining capacity of the battery is a second predetermined value (for example, 65
%) Or more, the operation of the engine is stopped, and the power generation is stopped.

Here, during operation of the engine (ie, during power generation), the engine is operated with characteristics as shown in FIGS. First, a power generation amount instruction value (target power generation amount) is set from the map shown in FIG. 7 based on the accelerator pedal depression amount of the driver. The target power generation amount is set to a value in which the power generation amount required for traveling is further taken into consideration so that the power generation amount of the vehicle has a certain margin so that the remaining capacity of the battery tends to recover. As shown in the figure, the target power generation amount is set to a step-like characteristic. For example, when the accelerator depression amount exceeds 10%, the target power generation amount is changed from 10 kW to 20 kW.

[0005] As shown in FIGS. 8 (a) and 8 (b), when the accelerator opening is increased by depressing the accelerator and the target power generation amount is changed, the throttle actuator attached to the throttle starts from this point. When activated, the throttle opening increases and the engine output increases.
As a result, the amount of power generation also increases, and the required power is obtained. The throttle actuator is constituted by a stepper motor or the like, and the throttle opening is adjusted by appropriately changing a control signal for the stepper motor.

This will be described with reference to a flowchart shown in FIG. 9. When the engine is operating, first, at step S1
At 0, the target power generation amount is set based on the accelerator depression amount. Then, in step S20, a target throttle opening is set based on the target power generation amount, and in step S30, the throttle actuator is driven to achieve the target throttle opening, and the throttle is opened and closed.

[0007]

However, FIG.
As shown in (a) and (b), conventionally, the rate of change of the throttle opening (throttle changing speed) is constant irrespective of the depressing speed of the accelerator opening. There was a problem that I felt uncomfortable with the change of.

That is, even in a series hybrid electric vehicle in which the engine and the driving wheels are not mechanically connected, for example, when the driver steps on the accelerator quickly, it is better for the driver to quickly increase the rotation speed of the engine. However, since the operation speed of the throttle actuator is a constant value in the related art, it may not match the driver's feeling in some cases. Also,
If the driver steps on the accelerator quickly, the remaining capacity of the battery decreases and the battery voltage decreases from the increase in the power generation instruction value to the actual increase in the power generation, and as a result, the output of the motor is suppressed. There is a problem that running performance is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made to reduce the uncomfortable feeling of the engine rotation with respect to the accelerator operation, and to prevent the battery voltage from being lowered when the accelerator is quickly depressed. It is an object to provide an engine operation control device for a hybrid electric vehicle.

[0010]

According to the first aspect of the present invention, there is provided an engine operation control device for a hybrid electric vehicle.
When the accelerator pedal depression amount is detected by the accelerator pedal depression amount detector, the accelerator pedal depression speed calculator calculates the accelerator pedal depression speed based on this detection information.

In the target throttle opening change rate setting means, the change rate of the target throttle opening of the engine during power generation is set according to the accelerator depression speed. As a result, when the accelerator is quickly depressed, the rate of change of the target throttle opening of the engine is set to a large value, and the engine speed increases quickly.
It is possible to eliminate a sense of incongruity with the accelerator operation.

Further, in the engine operation control device for a hybrid electric vehicle according to the present invention, the first target power generation amount setting means sets the target power generation of the generator based on the detection information from the accelerator depression amount detection means. The amount is set and based on the required output required by the motor,
The target power generation amount of the generator is set by the second target power generation amount setting means.

The selection means selects the larger one of the target power generation amounts set by the first and second target power generation amount setting means, based on the target power generation amount set by the selection means. The target throttle opening of the engine is set. As a result, during power generation running with the engine,
The engine can be operated such that the remaining capacity of the battery tends to recover.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a hybrid electric vehicle according to an embodiment of the present invention; FIG. Battery 1 is an electric motor (motor) via motor controller 2
3 is electrically connected. The motor 3 is connected to a drive wheel side of a vehicle (not shown), and the hybrid electric vehicle runs by driving the motor 3.

An engine 4 is also provided in the hybrid electric vehicle, and a generator 5 for supplying power to the battery 1 and the motor 3 is mechanically connected to an output side of the engine 4. Then, the generator 4 is driven by the engine 4.
Is driven, electric power corresponding to the load of the generator 5 is generated. Further, the vehicle is provided with a control device (or simply referred to as a controller) 6 as control means to which various sensors are connected, and the engine 4 and the generator 5 receive control signals from the controller 6. The operation is controlled based on the operation.

On the other hand, the accelerator pedal 7 is provided with an accelerator opening sensor (accelerator depression amount detecting means) 8.
An output corresponding to the depression amount of the accelerator pedal 7 by the driver is input to the motor controller 2 and the controller 6. An instruction output to the motor 3 is set by the motor controller 2 based on the output signal of the accelerator opening sensor 8, and the motor 3 is driven according to the instruction output to the motor 3.

Further, the battery 1 is provided with a remaining capacity detecting means (specific gravity meter) 10 for detecting the remaining power of the electric power. The remaining capacity of the battery 1 is detected by the specific gravity meter 10 and inputted to the controller 6. It has become so.
Normally, when the remaining capacity of the battery 1 is equal to or more than a first predetermined value (for example, 60%), the vehicle is driven by the electric power stored in the battery 1, and the remaining capacity of the battery 1 becomes equal to the first predetermined value. When it is less than the predetermined value, the engine 4 is operated to drive the generator 5. Then, at this time, the vehicle is run using the electric power generated by the generator 5, and the battery 1 is charged at the same time. When the remaining capacity of the battery 1 recovers to a second predetermined value (for example, 65%) or more by the charging at this time,
The operation of the engine 4 is stopped.

Further, the engine 4 is provided with a water temperature sensor (water temperature detecting means) 22 for detecting the temperature of the cooling water in the water jacket 21. When the engine 4 starts, the water temperature becomes a predetermined temperature (for example, 60 ° C.). If it is less than the predetermined value, the controller 6 executes the warm-up operation of the engine 4. Note that power generation is not performed during the warm-up operation.

During normal operation of the engine 4 (during power generation), the output of the engine 4 is controlled in accordance with the required power generation (target power generation). That is, when the target power generation amount is large, the throttle attached to the engine 4 is opened to increase the engine rotation speed, and when the target power generation amount is small, the throttle is closed to suppress the engine rotation speed. ing.

The throttle is an actuator for driving a throttle valve to change the throttle opening (throttle actuator, see reference numeral 4a in FIG. 2).
The operation of the actuator 4a is controlled by a control signal from the controller 6. Note that, for example, a stepper motor is applied as the throttle actuator 4a.

As shown in FIG. 2, the controller 6 is provided with an accelerator depression speed calculating means 61 and a target throttle opening change rate setting means 62.
The accelerator depression speed calculating means 61 calculates the rate of change of the accelerator opening (that is, the accelerator depression speed) based on the detection information from the accelerator opening sensor 8. The target throttle opening change rate setting means 62 sets the target throttle opening change rate (target throttle change speed) of the engine 4 when the engine 4 is operating (that is, during power generation).

Here, the target throttle opening change rate setting means 62 stores, for example, a map as shown in FIG. 3B, and the accelerator depression speed calculating means 61.
The target throttle change speed is set in accordance with the accelerator depressing speed calculated in (1). Specifically, the faster the accelerator pedal is depressed, the higher the target throttle change speed is set. The characteristic for setting the target throttle change speed is shown in FIG.
However, the present invention is not limited to those described above, and other characteristics may be used as long as they have a characteristic that the throttle change speed increases at least as the accelerator opening increases.

When the target throttle change rate is set by the target throttle opening change rate setting means 62,
The controller 6 outputs a control signal to the throttle actuator 4a so that the change speed of the throttle opening becomes the target throttle change speed. As shown in the figure, the controller 6 is provided with a first target power generation amount setting means 63, a second target power generation amount setting means 64, and a selection means 65. The opening is set.

Among them, the first target power generation amount setting means 63
The second target power generation amount setting unit 64 is a unit that individually sets the target power generation amount based on different parameters, and the selection unit 65 is set by the target power generation amount setting units 63 and 64. This is a means for comparing the values and selecting the larger value. Here, the first target power generation amount setting means 63 is provided with a map as shown in FIG. 4A, and the target is set in a stepwise manner based on the accelerator depression amount, similarly to the above-described conventional technology. The amount of power generation is set. Further, the second target power generation amount setting means 64 is provided with a map as shown in FIG.
The target power generation amount is set from the required output of the motor 3. The required output of the motor 3 is calculated from the power consumption of an inverter (not shown) attached to the motor 3.

The selector 65 selects the larger one of the two target power generation amounts. As shown in FIG.
A map for converting the selected target power generation amount into a throttle opening is provided, and the target throttle opening of the throttle actuator 4a is set using this map.

By selecting the larger one of the two target power generation amounts, the engine 4 is operated such that the remaining capacity of the battery 1 tends to recover during the power generation traveling by the engine 4. You can do it. Note that the target power generation amount may be simply set based on the accelerator depression amount without providing the second target power generation amount setting means 64 and the selection means 65.

Since the engine operation control apparatus for a hybrid electric vehicle according to one embodiment of the present invention is configured as described above, the throttle actuator 4a is driven based on, for example, a flowchart shown in FIG.
That is, when the engine 4 is operating (except during the warm-up operation), the first target power generation amount setting means 63 is set based on the accelerator depression amount obtained from the accelerator sensor 8.
The target power generation amount is set step by step, and the target power generation amount is set step by step from the required output of the motor 3 by the second target power generation setting means 64, and the larger one of these is selected by the selection means 65 Is performed (step S1). And FIG.
A target throttle opening corresponding to the selected target power generation amount is set from a map as shown in (a) (step S2).

On the other hand, based on the detection information from the accelerator opening sensor 8, the accelerator depression speed calculating means 61 calculates the rate of change of the accelerator opening (that is, the accelerator depression speed). Then, the target throttle opening change rate setting means 62 sets the target throttle change speed in accordance with the accelerator depression speed from a map as shown in FIG. 3B (step S3).

When the target throttle change speed and throttle opening are calculated in this way, the controller 6 determines whether the throttle valve opening and its change speed are equal to the target throttle opening and target throttle change speed. Thus, the throttle actuator 4a is driven (step S4). Therefore, FIGS. 5 (a) and 5 (b)
As shown in FIG. 5, the accelerator pedal is depressed during the power generation traveling by the engine 4 (see the upper graph in the figure), thereby increasing the target power generation by one step (see the middle graph), the controller 6 sends a control signal to the actuator 4a. Is output, and the throttle opening is changed in accordance with the control signal (see the lower graph).

At this time, as shown in FIGS. 5 (a) and 5 (b), even if the accelerator depression speed (the gradient of the graph) is different, if the accelerator depression amount is the same, the throttle opening which is consequently changed is changed. Although the degree itself is the same, the rate of change of the throttle opening is set according to the accelerator depression speed, so if the accelerator is quickly depressed, the engine speed will increase quickly and the accelerator will be released slowly. When depressed, the engine speed slowly increases, and the driver does not feel uncomfortable.

As described above, according to the engine operation control device for a hybrid electric vehicle according to one embodiment of the present invention, the rate of change of the target throttle opening of the engine 4 during power generation is set according to the accelerator depression speed. Therefore, the change rate of the target throttle opening degree of the engine 4 is set to be large when the accelerator pedal is quickly pressed, and the engine speed is quickly increased, so that it is possible to eliminate a sense of discomfort due to the accelerator operation, and to provide a driver's feeling. There is an advantage that the operation of the engine 4 can be performed in accordance with the above.

Further, when the driver depresses the accelerator quickly, the engine speed rapidly increases, so that the time from the increase in the target power generation amount to the actual increase in the power generation amount can be reduced, and the engine rotation speed can be reduced. There is an advantage that it is possible to reliably prevent a situation in which the remaining capacity of the battery 1 further decreases before the speed increases and the running performance decreases.

Furthermore, since the control logic only needs to be changed without adding any new parts to the configuration of the conventional hybrid electric vehicle, there is an advantage that the cost and weight do not increase. . Further, a larger value is selected from the target power generation amount set based on the detection information of the accelerator sensor 8 and the target power generation amount set based on the required output required by the motor 3, and the selected value is selected. Since the target throttle opening of the engine 4 is set based on the target power generation amount, the engine 4 can be operated such that the remaining capacity of the battery tends to recover during power generation traveling by the engine 4. There are advantages too.

The engine operation control device for a hybrid electric vehicle according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the present invention is not limited to a series-type hybrid electric vehicle, but can be widely applied to a hybrid electric vehicle having at least a mode in which an engine is operated for power generation.

[0035]

As described above in detail, according to the engine operation control apparatus for a hybrid electric vehicle according to the first aspect of the present invention, the target throttle opening of the engine at the time of power generation based on the depression speed of the accelerator pedal of the driver. Since the rate of change of the degree is set, there is an advantage that the engine can be operated in accordance with the driver's feeling.

Also, when the driver steps on the accelerator quickly, the engine speed increases quickly, so that the time until the power generation actually increases can be shortened. There is an advantage that it is possible to reliably prevent a situation in which the remaining capacity of the battery is reduced and the running performance is reduced. Further, the configuration of the conventional hybrid electric vehicle only needs to be changed in the control logic, and there is no need to add any new parts, so that there is an advantage that the cost and weight do not increase.

Further, according to the engine operation control device for a hybrid electric vehicle of the present invention, the target power generation amount set based on the detection information from the accelerator depression amount detecting means and the electric motor are required. Since the target throttle opening of the engine is set based on the larger target power generation amount of the target power generation amount set based on the required output, the engine is designed to ensure that the remaining capacity of the battery tends to recover. There is an advantage that can be driven.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a hybrid electric vehicle to which the present invention is applied.

FIG. 2 is a schematic block diagram illustrating a main configuration of an engine operation control device of the hybrid electric vehicle according to the embodiment of the present invention.

FIGS. 3A and 3B are diagrams for explaining the operation of the engine operation control device of the hybrid electric vehicle according to the embodiment of the present invention, wherein a target throttle opening and a target throttle change of the engine are respectively shown. It is a map for setting a speed.

FIGS. 4A and 4B are diagrams for explaining the operation of the engine operation control device of the hybrid electric vehicle according to one embodiment of the present invention, and are maps for setting a target power generation amount. .

FIGS. 5A and 5B are diagrams illustrating the operation of an engine operation control device for a hybrid electric vehicle according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation of the engine operation control device of the hybrid electric vehicle according to one embodiment of the present invention.

FIG. 7 is a diagram for explaining a conventional technique.

FIG. 8 is a diagram for explaining a conventional technique.

FIG. 9 is a diagram for explaining a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 3 Electric motor (motor) 4 Engine 5 Generator 6 Control means (controller) 7 Accelerator pedal 8 Accelerator depression amount detecting means (accelerator sensor) 61 Accelerator depression speed calculating means 62 Target throttle opening change rate setting means 63 First Target power generation amount setting means 64 Second target power generation amount setting means 65 Selection means

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3G084 BA02 BA05 BA13 BA34 CA04 DA03 DA05 DA11 EB08 FA03 FA10 FA13 FA32 3G093 AA01 AA07 AA16 BA15 CA05 CB06 DA06 DB28 EA09 EB09 EC02 FA07 FA12 FB01 3G301 HA01 HA27 JA03 JA04 JA10 JA01 LB01 LC04 LC10 MA11 NA08 NB02 NB06 NB20 NC04 NE01 PA11Z PB03Z PE06Z PF03Z PF12Z PG01Z PG02Z 5H115 PA01 PC06 PG04 PI16 PI23 PI29 PU08 PU26 PV09 QE08 QN24 RE01 RE03 SE02 TE01 TE03 TE08 TI02 TO14 TO21 TO21

Claims (2)

[Claims] 1. An engine operation control device for a hybrid electric vehicle including at least an electric motor and an engine, comprising: accelerator depression amount detection means for detecting an accelerator depression amount; and detection information from the accelerator depression amount detection means. Accelerator depressing speed calculating means for calculating the depressing speed of the accelerator pedal based on the accelerator pedal depressing speed; and a rate of change of the target throttle opening during power generation operation of the engine based on the accelerator depressing speed calculated by the accelerator depressing speed calculating means. And a target throttle opening change rate setting means for setting the target throttle opening degree. 2. A generator driven by the engine; first target power generation amount setting means for setting a target power generation amount of the generator based on detection information from the accelerator depression amount detection means; A second target power generation amount setting means for setting a target power generation amount of the generator from a required output required by the power generator, and a target power generation amount set by the first and second target power generation amount setting means, 2. The engine of a hybrid electric vehicle according to claim 1, further comprising selection means for selecting a target throttle opening, wherein a target throttle opening of the engine is set based on the target power generation amount set by the selection means. Operation control device.