Hybrid vehicle control apparatus

• US 6,741,917 B2
• Filed: 01/18/2002
• Issued: 05/25/2004
• Est. Priority Date: 02/05/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tomikawa, Saburo
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US10/050,139
• Publication Number:
  US 20020107617A1
• Time in Patent Office: 858 Days
• Field of Search: 701/22, 701/69, 180/65.2, 180/65.8
• US Class Current: 701/22
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 2050/0042 Transfer function lag; delays
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/916 : with plurality of drive axles
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio

Abstract

A hybrid vehicle control apparatus controls an engine that rotates at least one first wheel and a mechanically independent electric motor that rotates at least one second wheel. The hybrid vehicle control apparatus stabilizes the vehicle driving performance when there is a change in the portion of the total drive torque that should be carried by the engine. Thus, the hybrid vehicle control apparatus prevents degradation of the vehicle driving performance due to the response of the engine when the drive force distribution is shifted. The target drive torque of the engine driven wheels is calculated by multiplying the total target drive torque by a rear wheel drive force distribution ratio. The target drive torque of the motor driven wheels is calculated by estimating the actual drive torque of the engine driven wheels and subtracting this estimated value from the total target drive torque.

Claims

1. A hybrid vehicle control apparatus for a vehicle having front and rear wheels with at least one of the front and rear wheels being an engine driven wheel driven by an internal combustion engine and at least one of the front and rear wheels being a non-engine driven wheel driven by an electric motor that is mechanically independent from the engine, the hybrid vehicle control apparatus comprising:

a total target drive torque setting section configured to set a total target drive torque of the engine driven wheel and the non-engine driven wheel;

a target engine torque setting section configured to set a target engine torque, which is a portion of the total target drive torque that should be produced at the engine driven wheel; and

a motor command value setting section configured to set a torque command value for the electric motor in a delayed manner with respect to a change in a target drive torque of the electric motor when the target engine torque changes, the torque command value corresponds to a distribution ratio of the total target drive torque that should be produced at the non-engine driven wheel.

2. The hybrid vehicle control apparatus as recited in claim 1, wherein

the motor command value setting section includes

a real engine torque estimating section configured to estimate an estimated real engine torque, which is an actual drive torque of the engine driven wheel during convergence on the target engine torque after the change in the target drive torque of the electric motor, and

a subtracting section configured to subtract the estimated real engine torque from the total target drive torque.

3. The hybrid vehicle control apparatus as recited in claim 2, wherein

the real engine torque estimating section is further configured to estimate the estimated real engine torque based on a delay time constant that is based on at least one of a rotational speed of the engine, an air intake pressure, and a throttle opening.

4. The hybrid vehicle control apparatus as recited in claim 1, wherein

the motor command value setting section is configured to set a larger value for the torque command value upon determining acceleration being requested than upon determining acceleration is not being requested.

5. The hybrid vehicle control apparatus as recited in claim 4, wherein

the motor command value setting section includes

a real engine torque estimating section configured to estimate an estimated real engine torque, which is an actual drive torque of the engine driven wheel during convergence on the target engine torque after the change in the target drive torque of the electric motor, and

a subtracting section configured to subtract the estimated real engine torque from the total target drive torque.

6. The hybrid vehicle control apparatus as recited in claim 5, wherein

the motor command value setting section is configured to set the larger value for the torque command value by having the real engine torque estimating section estimate a smaller real engine torque when acceleration is being requested.

7. A hybrid vehicle control apparatus as recited in claim 1, further comprising

a motor command value adjusting section configured to adjust the torque command value for the electric motor to a smaller value upon determining slippage of the engine driven wheel, than upon determining there is no slippage.

8. The hybrid vehicle control apparatus as recited in claim 7, wherein

the motor command value adjusting section is further configured to determine the slippage is occurring based on a difference in rotational speed between the engine driven wheel and the non-engine driven wheel.

9. The hybrid vehicle control apparatus as recited in claim 1, wherein

the motor command value setting section is further configured to set the torque command value for the electric motor to the target drive torque of the electric motor, which corresponds to a distribution ratio of the total target drive torque that should be produced at the non-engine driven wheel, when there is slippage of the non-engine driven wheel.

10. A vehicle drive transmission system comprising:

an internal combustion engine;

an electric motor that is mechanically independent from the engine;

front and rear wheels with at least one of the front and rear wheels being an engine driven wheel driven by the internal combustion engine and at least one of the front and rear wheels being a non-engine driven wheel driven by the electric motor; and

a hybrid vehicle control apparatus including

a total target drive torque setting section configured to set a total target drive torque of the engine driven wheel and the non-engine driven wheel;

a torque engine torque setting section configured to set a target engine torque, which is a portion of the total target drive torque that should be produced at the engine driven wheel; and

a motor command value setting section configured to set a torque command value for the electric motor in a delayed manner with respect to a change in a target drive torque of the electric motor when the target engine torque changes, the torque command value for the electric motor corresponds to a distribution ratio of the total target drive torque that should be produced at the non-engine driven wheel.

11. The vehicle drive transmission system as recited in claims 10, wherein

the motor command value setting section includes

a real engine torque estimating section configured to estimate an estimated real engine torque, which is an actual drive torque of the engine driven wheel during convergence on the target engine torque after the change in the target drive torque of the electric motor, and

a subtracting section configured to subtract the estimated real engine torque from the total target drive torque.

12. The vehicle drive transmission system as recited in claim 11, wherein

the real engine torque estimating section is further configured to estimate the estimated real engine torque based on a delay time constant that is based on at least one of a rotational speed of the engine, an air intake pressure, and a throttle opening.

13. The vehicle drive transmission system as recited in claims 10, wherein

the motor command value setting section is configured to set a larger value for the torque command value upon determining acceleration being requested than upon determining acceleration is not being requested.

14. The vehicle drive transmission system as recited in claim 13, wherein

the motor command value setting section includes

a real engine torque estimating section configured to estimate an estimated real engine torque, which is an actual drive torque of the engine driven wheel during convergence on the target engine torque after the change in the target drive torque of the electric motor, and

a subtracting section configured to subtract the estimated real engine torque from the total target drive torque.

15. The vehicle drive transmission system as recited in claim 14, wherein

the motor command value setting section is configured to set the larger value for the torque command value by having the real engine torque estimating section estimate a smaller real engine torque when acceleration is being requested.

16. The vehicle drive transmission system as recited in claims 10, further comprising

a motor command value adjusting section configured to adjust the torque command value for the electric motor to a smaller value upon determining slippage of the engine driven wheel, than upon determining there is no slippage.

17. The vehicle drive transmission system as recited in claim 16, wherein

the motor command value adjusting section is further configured to determine the slippage is occurring based on a difference in rotational speed between the engine driven wheel and the non-engine driven wheel.

18. The vehicle drive transmission system as recited in claim 10, wherein

the motor command value setting section is further configured to set the torque command value for the electric motor to the target drive torque of the electric motor, which corresponds to a distribution ratio of the total target drive torque that should be produced at the non-engine driven wheel, when there is slippage of the non-engine driven wheel.

19. A hybrid vehicle control apparatus for a vehicle having front and rear wheels with at least one of the front and rear wheels being an engine driven wheel driven by an internal combustion engine and at least one of the front and rear wheels being a non-engine driven wheel driven by an electric motor that is mechanically independent from the engine, the hybrid vehicle control apparatus comprising:

a total target drive torque setting means for setting a total target drive torque of the engine driven wheel and the non-engine driven wheel;

a target engine torque setting means for setting a target engine torque, which is a portion of the total target drive torque that should be produced at the engine driven wheel; and

a motor command value setting means for setting a torque command value for the electric motor in a delayed manner with respect to a change in a target drive torque of the electric motor when the target engine torque changes, the torque command value corresponds to a distribution ratio of the total target drive torque that should be produced at the non-engine driven wheel.

20. The hybrid vehicle control apparatus as recited in claim 19, wherein

the motor command value setting means includes

a real engine torque estimating means for estimating an estimated real engine torque, which is an actual drive torque of the engine driven wheel during convergence on the target engine torque after the change in the target drive torque of the electric motor, and

a subtracting means for subtracting the estimated real engine torque from the total target drive torque.