JP2003009306A - Hybrid vehicle control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the power difference between power generation and power consumption of a generator and a motor, and to reduce the size of a battery. The vehicle includes an engine, a generator connected to the engine, a motor serving as a power source of a vehicle, and a battery that is charged and discharged by a power output of the generator and power consumption of the motor. . Means for estimating the torque of the generator 2; means for calculating the engine friction based on the estimated generator torque in a vehicle running state in which fuel supply to the engine 1 is stopped and the engine is driven by the generator. And control means for using the calculated engine friction as a control element of the engine 1 or the generator 2. As a result, the output of the engine 1 or the generator 2 can be accurately matched with the target value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hybrid vehicle.

[0002]

2. Description of the Related Art There is a hybrid drive system (HEV) which is a combination of an engine, a power generator, and an electric motor as a drive source of a vehicle excellent in low pollution. In this HEV, there are a series type and a parallel type depending on the combination method of the engine, the power generation, and the electric motor, but even if the series type is used, if the energy consumed by the electric motor can be supplied from the generator without excess or deficiency, the battery can be used. It is possible to reduce the charge / discharge loss and reduce the size of the battery, which is extremely advantageous in terms of cost, fuel efficiency, and power performance.

From this point of view, conventionally, Japanese Patent Laid-Open No. 11-146 has been proposed.
Japanese Patent No. 503 proposes to associate the drive output of the electric motor, which changes according to the running state of the vehicle, with the power generation amount of the generator.

Further, as disclosed in Japanese Patent Laid-Open No. 8-79914, the engine is driven by a generator when the amount of battery charge approaches a saturated state during regenerative braking, so that the braking characteristic required for the vehicle is ensured and the battery Some prevent overcharging.

[0005]

By the way, in order to make the generator driven by the engine generate the target electric power, the torque of the engine for driving the generator is controlled and the rotation speed of the generator is controlled. ing.

Therefore, the target power output of the generator is divided by the generator efficiency to obtain the generator driving power, which is divided by the actual rotation speed (= engine rotation speed) of the generator to obtain the target engine torque. The throttle valve opening of the engine, the fuel injection amount, the ignition timing, etc. are controlled so that the engine exerts this target engine torque.

This control is basically performed by open control. That is, an experiment using a standard engine is performed to map the relationship between the engine torque and the control value (throttle valve opening, fuel injection amount, ignition timing, etc.) in advance,
When actually controlling the engine, the control value read from this map according to the target engine torque is used to control the engine.

However, if there is an individual difference in friction between the engine used to create the map and the actual engine, the engine torque as intended cannot be obtained even if control is performed according to the map, and the actual friction is large. If so, the power output of the generator will be lower than the target. In this case, even with the same engine, there is a problem that the friction changes with time due to deterioration of lubricating oil or wear of the piston ring.

As a result, when the actual engine torque does not match the target, the power generation output of the generator also does not match the target, and there is a difference between the power consumption of the motor and the charge / discharge of the battery, or in some cases. Will cause overcharge.

An object of the present invention is to accurately obtain the friction of an engine in a hybrid drive system, eliminate the difference in power generation and power consumption between a generator and an electric motor, and reduce the battery capacity.

[0011]

SUMMARY OF THE INVENTION A first aspect of the present invention provides an engine, a generator connected to the engine, an electric motor serving as a power source of a vehicle, a power output of the generator and power consumption of the electric motor. In a hybrid vehicle including a battery that discharges, a means for estimating the torque of the generator and the generator estimated torque in the vehicle running state in which the engine fuel supply is stopped and the engine is driven by the generator A means for calculating an engine friction based on the engine friction and a control means for using the calculated engine friction as a control element of an engine or a generator.

In a second aspect, the torque estimating means in the first aspect estimates the generator torque based on the detected value of the current flowing through the stator coil of the generator.

In a third invention, the engine friction calculating means in the first invention calculates the engine friction torque by subtracting the engine pumping loss torque at that time from the generator estimated torque.

In a fourth aspect based on the first or third aspect, the calculated engine friction is stored and the stored value is sequentially updated.

In a fifth aspect based on the first to fourth aspects, the control means corrects the engine target torque required to drive the generator based on the calculated engine friction.

In a sixth aspect based on the first to fourth aspects, the control means calculates a generator target rotational speed when the engine is driven by the generator based on the calculated engine friction.

[0017]

According to the present invention, since the engine friction is calculated from the estimated engine torque when the engine is driven by the generator, the engine friction can be accurately calculated, and the engine or the generator is controlled based on this. Therefore, the target engine torque and the generator output can be controlled accurately even if there are individual differences in the engine or changes over time, and the generated power and consumed power of the generator and motor can be matched and required by the battery. It is possible to reduce the charging / discharging performed, reduce the charging / discharging loss of the battery, and further reduce the battery capacity.

Further, in the fourth aspect of the present invention, the engine friction is updated to the latest value, so that the engine and generator can always be controlled accurately.

According to the fifth aspect of the present invention, the power output of the generator can be accurately controlled in accordance with the required driving force of the electric motor, the difference between the electric power generation and the electric power consumption of the electric generator can be eliminated, and the charge / discharge of the battery can be reduced. However, the battery capacity can be further reduced.

In the sixth aspect of the invention, the power consumption of the generator and the regenerative power of the electric motor can be accurately matched when the deceleration energy for driving the engine by the generator is regenerated.
The charge and discharge of the battery can be suppressed, and the battery can be downsized in the same manner as above.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, FIG. 1 is a system configuration diagram of a vehicle to which the present invention is applied. A generator 2 driven by the engine 1 and an electric motor 4 driven by the output of the generator 2.
The electric power train 5 including the generator 2 and the electric motor 4 also functions as a continuously variable transmission of the vehicle.

The rotor shaft of the generator 2 is connected to the crank shaft of the engine 1, and the rotor shaft of the electric motor 4 (hereinafter referred to as the output shaft) 6
Is connected to the drive shaft 7 to which the drive wheel 7a is attached via a differential.

The generator 2 and the electric motor 4 are AC machines such as permanent magnet type AC synchronous motors, and are connected to an inverter 8. The rotation speeds of the generator 2 and the electric motor 4 are controlled according to the drive frequency of the inverter 8, and the ratio of the drive frequency of the inverter 8 becomes the rotation speed ratio (gear ratio) of the input / output shaft of the electric power train 5. The inverter 8 has a battery 9
(Lithium battery or NiMH battery, etc.) is connected.

A clutch 3 is interposed between the generator 2 and the electric motor 4. When the clutch 3 is engaged, the engine 1 and the output shaft 6 are directly connected to each other and the engine 1 directly connects the output shaft 6 to the output shaft 6. Can be driven. The clutch 3 is engaged, for example, when the generator rotation speed of the electric power train 5 and the electric motor rotation speed match, and it is possible to suppress loss in the generator 2 and the electric motor 4 and improve fuel economy performance of the vehicle.

For the control described later, the electric power train 5 has a generator rotation speed sensor 2 for detecting a rotor rotation speed Ni of the generator 2 (hereinafter referred to as a generator rotation speed) Ni.
4 and a motor rotation speed sensor 21 that detects a rotor rotation speed (hereinafter, motor rotation speed) No of the motor 4 are attached. Furthermore, a current sensor 25 for detecting the current flowing through the stator coil of the generator 2 is provided.

On the other hand, an electronically controlled throttle device 14 is provided in the intake passage of the engine 1, and the driver operates the throttle opening so that a target engine torque set according to the required generated electric power is realized. It is controlled independently of the accelerator operation. In addition to this, the engine 1 is provided with an air flow meter 13 for detecting the intake air amount and a crank angle sensor 23 for detecting the crank angle.

An integrated control unit (GCU) 10 for controlling the engine 1 and the electric power train 5.
The transmission control unit (TCU) 12 is basically provided to obtain a driving force required by the driver based on the accelerator operation amount detected by the accelerator operation amount sensor 22 and the like, and to realize the required driving force.
The torque of the electric motor 4 is controlled via the. Also, the electric motor 4
The rotational speed control of the generator 2 via the transmission control unit 12 and the torque control of the engine 1 via the engine control unit (ECU) 11 are also performed so that the generated power corresponding to the drive output (power consumption) of the engine is obtained. Do it together.

Further, the integrated control unit 10
When the vehicle is decelerating (fuel cut), the electric motor 4 is made to function as a generator to regenerate electric power, and this regenerated electric power is further consumed by making the generator 2 as an electric motor to perform power consumption. Balance the balance.

FIG. 2 is a block diagram showing the contents of vehicle control performed by the integrated control unit 10.

Explaining this, in block B1, the accelerator pedal operation amount APO [deg] and the vehicle speed VSP
The target driving force tFd0 [N] is calculated based on [km / h]. The target driving force tFd0 is specifically calculated by referring to a predetermined target driving force map according to the accelerator pedal operation amount APO and the vehicle speed VSP. The driving force map is set according to the state of supplying fuel to the engine. The accelerator pedal operation amount APO is detected by the accelerator operation amount sensor 22, and the vehicle speed VSP is the motor rotation speed 21.
It is calculated by multiplying the rotation speed No [rpm] of the electric motor 4 detected by the sensor by a constant G1. The radius of the vehicle drive wheels is r
[M], where R is the reduction ratio from the output shaft of the electric motor 4 to the drive wheel shaft, the constant G1 is G1 = 2 × π × r × 60 /
It is a value calculated by (R × 1000).

In block B2, the target driving force tFd0
The target motor output tPo00 [W] is calculated by multiplying [N] by the vehicle speed VSP [m / s]. The vehicle speed VSP is the motor rotation speed No [rp detected by the motor rotation speed sensor 22.
It is calculated by multiplying m] by a constant G2. The constant G2 is G1 =
It is a value calculated by 2 × π × r / (R × 60).

In block B3, the target motor output tPo0
The filter process is applied to 0 [W]. This filtering process is performed to reduce the apparent control response speed of the electric motor 4.

In block B4, the vehicle speed VSP [km / h]
The target driving force tFd_d [N] at the time of fuel cut is calculated based on Specifically, the fuel cut target driving force tFd_d is calculated according to the vehicle speed VSP by referring to the fuel cut target driving force table. The target drive force tFd_d during fuel cut is set to a negative value (indicating that the vehicle drives the electric motor 4) except for the extremely low vehicle speed range.

In block B5, the target driving force tFd_d [N] at fuel cut is multiplied by the vehicle speed VSP [m / s] to calculate the target electric motor regenerative power tPo_d [W] at fuel cut. Target motor regenerative power at fuel cut tPo_d
Represents the target value of the regenerative output of the electric motor 4 (= the kinetic energy of the vehicle consumed per unit time by the regenerative driving of the electric motor 4).

In block B6, the target motor output is selected based on the fuel cut determination flag fFCUT,
When the flag fFCUT is zero (non-fuel cut), the target motor output after filtering tPo0 [W] is selected, and when the flag fFCUT is 1 (fuel cut), the target motor regeneration output tPo_d [W] at fuel cut is selected. Is selected.

As shown in FIG. 3, the flag fFCUT determines whether or not the accelerator pedal is fully closed (the accelerator operation amount APO is substantially zero) with hysteresis (block B41), and the vehicle speed is predetermined. Whether or not the vehicle speed is higher than that is determined with hysteresis (block B4
2), it is set by ANDing both judgment results (block B43).

Returning to FIG. 2, block B7 is block B.
The target motor output selected in 6 is used as the motor rotation speed No.
The target motor torque tTo [N] is divided by [rad / s].
m] is calculated. Motor rotation speed No [rad / s]
Is calculated by multiplying the motor rotation speed No [rpm] detected by the motor rotation speed sensor 21 by a constant G3 (= 2 × π / 60).

The calculated target electric motor torque tTo is sent to the transmission control unit 12, and the torque of the electric motor 4 is controlled based on the target electric motor torque tTo. Particularly, when the target electric motor torque tTo has a negative value, the transmission control unit 12 controls the regenerative torque of the electric motor 4.

In block B8, the motor rotation speed No [r
The motor efficiency EFFm is calculated based on [pm] and the target motor torque tTo [Nm]. In block B9, the target electric motor output tPo00 [W] is divided by the electric motor efficiency EFFm to calculate the power consumption tPg [W] of the electric motor 4. When the fuel cut is not performed, direct power distribution is performed in which the electric power consumed by the electric motor 4 is generated by the generator 2 without excess or deficiency, so the electric motor power consumption tPg represents the target generated electric power of the generator 2.

In block B10, the generator rotation speed Ni
Generator efficiency E based on [rpm] and engine torque
FFg is calculated. The generator rotation speed Ni is detected by the generator rotation speed sensor 24. As the engine torque value, a value obtained by subjecting the output of the block B22 (target engine torque tTe [Nm]) described later to a predetermined delay process in block B11, or a block B19 described later.
Any of the outputs (engine brake torque Te_d [Nm]) selected in step B12 is used.

In block B12, when the fuel cut determination flag fFCUT is zero (non-fuel cut), block B1
When the flag fFCUT is 1 (fuel cut), the output of block B19 is selected.

In block B13, the target generator generated power t
The generator regeneration output tPe [W] is calculated by dividing Pg [W] by the generator efficiency EFFg. Since the generator 2 is driven by the engine 1, tPe represents the target engine output. In block B14, the target engine output tPe
The second target driving force tFd [N] is calculated by dividing [W] by the vehicle speed VSP [m / s].

In block B15, the target generator rotation speed tNi0 [rpm] is calculated based on the second target driving force tFd [N] and the vehicle speed VSP [km / h]. Specifically, the target generator rotation speed tNi0 is calculated by referring to a predetermined output distribution map according to the second target driving force tFd and the vehicle speed VSP.

At block B16, the target generator rotational speed t
Ni0 [rpm] is filtered. This filtering process is performed to slow the apparent control response speed of the generator 2. This filtering process is block B3.
It is the same as the filtering process of.

In block B17, the target driving force tFd_d [N] at the time of fuel cut is multiplied by the motor efficiency EFFm, and
Electric power generated by the electric motor 4 when fuel is cut (regenerative electric power) tPg
_D [W] is calculated. At the time of fuel cut, the electric power regenerated by the electric motor 4 is consumed by the generator 2 without excess or deficiency.
tPg_d is also the target generator power consumption at the time of fuel cut.

In block B18, the target generator power consumption tPg_d [W] is multiplied by the generator efficiency EFFg to calculate the generator output tPe_d [W] at the time of fuel cut.
At the time of fuel cut, the generator 2 rotationally drives the engine 1, so tPe_d represents the target engine brake output at the time of fuel cut.

In block B19, the generator rotation speed Ni
Based on [rpm] (= engine speed), the engine brake torque Te_d [Nm] at the time of fuel cut is calculated. Specifically, Te_d is set by referring to the engine brake torque table according to Ni, and Te_d is set.
Is set to a negative value. The negative value of Te_d indicates that the generator 2 drives the engine 1.

In block B20, the target engine brake output tPe_d [W] during fuel cut is divided by the engine brake torque Te_d [Nm] during fuel cut, and the target generator rotational speed tNi_d [rad /
s] is calculated.

In block B21, the final target generator rotational speed tN is determined based on the fuel cut determination flag fFCUT.
if is selected. When the flag fFCUT is zero (non-fuel cut), the target generator rotation speed t after filtering
When the flag fFCUT is 1 (fuel cut), Ni [rpm] is unit-converted using the constant G4 (= 1 / G3), and the target generator rotational speed tNi_d [r at fuel cut is converted.
pm] is selected as the final target motor rotation speed tNif.

The final target generator rotation speed tNif is the transmission control unit 1
2, and the rotation speed of the generator 2 is controlled based on this tNif.

On the other hand, in block B22, the target engine output tPe [W] is set to the generator rotation speed Ni [rad / s].
The target engine torque tTe [Nm] is calculated by dividing by. The generator rotation speed Ni [rad / s] is the generator rotation speed Ni [rpm] detected by the generator rotation speed sensor 24.
Is multiplied by a constant G3.

The calculated target engine torque tTe is sent to the engine control unit 11, and the torque of the engine 1 is controlled based on the target engine torque tTe.

Specifically, the electronically controlled throttle device 1
4, throttle opening, fuel injection amount, ignition timing, etc. are controlled.

However, the fuel cut determination flag fFCUT
When is 1, the fuel supply to the engine 1 is cut off, and in this case, the torque control of the engine 1 is interrupted.

Since the engine torque during non-fuel cut generally follows the throttle opening control with a predetermined delay, the filter processing of block B3 and block B12 is performed in such an engine. It is provided to synchronize the control of the electric motor and generator with the response delay of. On the other hand, since the engine braking torque at the time of fuel cut does not have the above delay, the target electric motor output and the target generator rotation speed at the time of fuel cut are not filtered.

By performing the above control, the electric power regenerated by the electric motor 4 at the time of fuel cut and the electric power consumption by the power running of the generator 2 can be matched, and the electric power balance can be balanced even during deceleration. The fluctuation of the battery state of charge (SOC) can be suppressed. Next, the calculation of the target combustion pressure torque of the engine performed by the engine control unit 11 based on the target engine torque tTe sent from the integrated control unit 10. The routine of FIG. 4 will be described.

In step S1, the fuel cut flag fF
It is determined whether the CUT is 0 (= no fuel cut).

When fFCUT is 0, that is, when the fuel is not cut, the routine proceeds to step S2, where the friction torque Tef of the engine 1 is calculated based on the actual engine speed Ni. Specifically, Tef is stored according to the current Ni from a friction torque table (Tef table) in which Tef is stored in association with the engine rotation speed.
Look up ef.

However, this friction torque is obtained in advance by experiments or the like, and there may be engine individual differences or changes over time, but this is corrected sequentially as will be described later (FIG. 5). .

In the next step S3, the pumping loss torque Tepl of the engine 1 is calculated based on the actual engine speed Ni and the throttle valve opening TVO. Specifically, Tepl is looked up according to the current Ni and TVO from a pumping loss torque map (Tep1 map) in which Tepl is stored in association with the engine rotation speed and the throttle valve opening.

Then, in step S4, the target engine torque t sent from the integrated control unit 10
The target combustion pressure torque tTc is calculated by adding Te, the friction torque Tef, and the pumping loss torque Tepl. Here, the combustion pressure torque is a pure torque generated by combustion of fuel, and the torque obtained by subtracting the torque due to friction and pumping loss from this combustion pressure torque is the output shaft torque that can be taken out from the engine.

On the other hand, if fFCUT is not 0 (= fuel cut) in step S1, the process proceeds to step S5, and the target combustion pressure torque tTc is set to 0.

A control value (throttle valve opening, fuel injection amount, ignition timing, etc.) is determined based on the target combustion pressure torque tTc calculated as described above, and engine control is performed using the control value.

By the way, as described above, the actual friction torque of the engine 1 may differ from the characteristics stored in advance due to individual differences among the engines, changes over time, and the like. Therefore, in the present invention, the actual friction torque is always calculated, and the stored value is sequentially updated based on the latest calculated value so that the target combustion pressure torque tTc of the engine 1, for example, can always be calculated accurately. ing.

This processing will be described according to the routine of FIG.

First, in step S11, it is determined whether the fuel cut flag fFCUT is 1 (= fuel cut).

If fFCUT is 1, step S1
Then, the routine proceeds to step 2 to judge whether or not the change amount ΔNi of the actual engine rotation speed Ni is smaller than the predetermined value ε.

When the variation ΔNi of the actual engine rotation speed Ni is smaller than the predetermined value ε, the process proceeds to step S13, where the actual engine rotation speed Ni (= actual generator rotation speed) and the generator 2
From the current Ig flowing in the stator coil of the generator 2
The actual torque Tg of is calculated.

In the next step S14, the pumping loss torque Tepl of the engine 1 is calculated based on the actual engine speed Ni and the throttle valve opening TVO (FIG. 4).
Same as step S3). Since fFCUT is 1, the throttle valve opening TVO at this time is 0 (fully closed).
Has become.

Then, in step S15, the generator 2
The pumping loss torque Tepl of the engine 1 is subtracted from the actual torque Tg of
Calculate fO.

When the engine 1 is in the fuel cut running state, the integrated control unit 10 balances the electric power balance even during deceleration by matching the electric power regenerated by the electric motor 4 and the electric power consumption by making the generator 2 power running. By doing so, fluctuations in the battery charge state are suppressed. That is, by driving the engine 1 whose output is stopped by the generator 2, the power corresponding to the electric energy regenerated by the electric motor 4 is consumed to prevent the fluctuation of the battery charge amount, while ensuring the deceleration performance of the vehicle. is doing.

Therefore, in this state, the actual torque of the generator 2 excluding the engine pumping loss is
It corresponds to the engine friction torque.

In step S16, the stored value in the Tef table is updated based on the actual engine rotation speed Ni and the current friction torque value TefO. For example, Ni
The weighted average value of Tef and TefO (see the following equation) looked up from the Tef table in accordance with the above is used as a new Tef to update the stored value.

Tef (new) = k × Tef + (1-k) × TefO In this way, the Tef table stored value corresponding to the actual friction torque of the engine 1 is updated during the fuel cut of the engine 1.

The value stored in the Tef table is assumed to be held even after the operation of the engine 1 or the vehicle is stopped. An experimental value using a standard engine is used as the initial value of the stored value.

On the other hand, if it is determined in step S12 that the amount of change ΔNi in the actual engine rotation speed Ni is greater than or equal to the predetermined value ε, T
The value stored in the ef table is not updated. This is because an accurate value may not be obtained even if the actual torque Tg of the generator 2 is calculated when the change in the actual engine rotation speed Ni is large.

If fFCUT is 0 in step S11, that is, if fuel cut is not in progress, step S11 is executed.
In step 17, it is determined whether or not the Tef table stored value has been updated.

Step S15 is executed during the fuel cut, and then the judgment in this step becomes YES only immediately after returning to the normal operation, and the process proceeds to step S18 to update the engine brake torque table (Te-d table). Be seen.

This engine brake torque can be obtained by adding the friction torque and the pumping loss torque when the throttle valve is fully closed, so that a new engine brake torque Te-d is calculated from the Tef table stored value and the Tepl map stored value. Calculated, and the stored value of the Te-d table is updated with this calculated value. Note that the Te-d table stored value is also held even after the operation of the engine or the vehicle is stopped.

In this routine, the Te-d table stored value is updated after the fuel cut operation is completed, but it can be done during the fuel cut (for example, immediately after step S15). However, the stored value of the Te-d table is used for controlling the rotation speed of the generator 2 during fuel cut, and if the stored value is updated and used at the same time, the control may become unstable, so it was avoided. Better.

Since the engine friction also changes depending on the engine temperature (= viscosity of lubricating oil),
In the warm-up process of the engine until the engine temperature reaches the equilibrium temperature, that is, when the friction torque Tef is calculated in step S2 of FIG. 4 and the value corrected according to the engine temperature is used in step S4, a more accurate result is obtained. Becomes Also, the engine friction is very large,
Since the control becomes unstable in the engine warm-up process (before the warm-up is completed), the routine of FIG. 5 is not executed.

As described above, according to the present invention, when the target engine torque from the integrated control unit 10 is applied to the engine control unit 11, when the target combustion pressure torque of the engine 1 is calculated, the friction of the engine 1 at that time is calculated. By calculating and correcting the combustion pressure torque based on this friction, the pure torque that the engine 1 can actually output to the outside is matched exactly with the required drive torque of the generator 2.

If the engine friction has a predetermined value based on an experimental value or the like, and if the actual friction fluctuates due to a change with time,
The generated engine torque deviates from the target value.

As a result, according to the present invention, it is possible to constantly reduce the difference between the electric power generated by the generator 2 and the electric power consumed by the electric motor 4, and the charge and discharge of the battery can be made as small as possible. Further, the battery capacity can be further reduced.

In the above description, the example in which the target combustion pressure torque of the engine 1 is calculated on the basis of the latest engine friction torque while updating the actual engine friction torque has been described. 1 stops the fuel supply and drives the engine 1 by the generator 2, the power consumption of the generator 2 is accurately controlled by modifying the target rotation speed of the generator 2 based on the engine friction torque. can do.

As described above, the integrated control unit 10 regenerates electric power by causing the electric motor 4 to function as a generator when the vehicle is decelerating (fuel cut), and further uses this regenerated electric power as the generator 2 as an electric motor. The electric power balance between the generator 2 and the electric motor 4 is balanced while ensuring the braking performance (engine braking) required for the vehicle by activating the engine 1 and driving it to drive it.

Therefore, if the target rotation speed of the generator 2 is calculated based on the actual engine friction torque, the power consumption required for the generator 2 to drive the engine 1 can be accurately controlled, and the electric motor 4 Power generation with the generator 2
It is possible to minimize the difference in power consumption. As a result, charging and discharging of the battery can be suppressed, and the capacity can be further reduced.

The present invention is not limited to the above-described embodiments, and it is obvious that various modifications can be made within the scope of the technical idea of the invention described in the claims.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a vehicle to which the present invention is applied.

FIG. 2 is a block diagram showing control contents of an integrated control unit.

FIG. 3 is a block diagram showing the contents of a fuel cut determination process.

FIG. 4 is a flowchart showing control contents.

FIG. 5 is a flowchart showing control contents.

[Explanation of symbols]

1 engine 2 generator 4 electric motor 10 Integrated control unit 11 Engine control unit 12 Transmission control unit 25 current sensor

Claims (6)

[Claims] 1. A hybrid vehicle including an engine, a generator connected to the engine, an electric motor that serves as a power source of the vehicle, and a battery that is charged and discharged by a power output of the generator and power consumption of the electric motor, Means for estimating the torque of the generator, means for calculating the engine friction based on the estimated torque of the generator in a vehicle traveling state in which the fuel supply to the engine is stopped and the engine is driven by the generator, A control device for a hybrid vehicle, comprising: a control unit that uses the calculated engine friction as a control element for an engine or a generator. 2. The control device for a hybrid vehicle according to claim 1, wherein the torque estimating means estimates the generator torque based on a detected value of a current flowing through a stator coil of the generator. 3. The control device for a hybrid vehicle according to claim 1, wherein the engine friction calculation means calculates the engine friction torque by subtracting the engine pumping loss torque at that time from the estimated generator torque. 4. The calculated engine friction is stored, and the stored value is sequentially updated.
A control device for a hybrid vehicle according to 1. 5. The control device for a hybrid vehicle according to claim 1, wherein the control means corrects the engine target torque required to drive the generator based on the calculated engine friction. . 6. The hybrid vehicle according to claim 1, wherein the control means calculates a generator target rotational speed when the engine is driven by the generator based on the calculated engine friction. Control device.