DRIVE CONTROL APPARATUS AND DRIVE CONTROL METHOD FOR HYBRID VEHICLE

• US 20110313602A1
• Filed: 01/05/2009
• Published: 12/22/2011
• Est. Priority Date: 01/16/2008
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hirata, Takeshi, Kaneko, Hiroshi
• Granted Patent: US 8,315,755 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• 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: B60W 2710/244 Charge state
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

Disclosed herein are embodiments of a drive control apparatus for hybrid vehicles and methods of driving control. In one such embodiment, a drive controller is configured to calculate a basic motor-generator torque value based on the basic engine torque value and the target driving torque value, set a target engine torque to be the basic engine torque value and set a target motor-generator torque as the basic motor-generator torque value when the state of charge of the battery is within an allowable range, set the allowable range of the battery to be smaller when the transmission is performing the shift change operation and execute a basic value shift process when the battery is deviated from the allowable range. The basic value shift process suppresses deviation of the battery by shifting the target engine torque from the basic engine torque value and the target motor-generator torque from the basic motor-generator torque value.

Claims

1. A drive control apparatus for a hybrid vehicle, comprising:

an engine;

a motor-generator;

a battery for supplying and receiving electric power to and from the motor-generator;

a transmission configured to perform a normal operation and a shift change operation; and

a controller configured to;

detect the normal operation and the shift change operation of the transmission;

determine a state of charge of the battery;

calculate a target driving torque value and a basic engine torque value based on a driving condition of the vehicle;

calculate a basic motor-generator torque value based on the basic engine torque value and the target driving torque value;

set a target engine torque to be the basic engine torque value and set a target motor-generator torque as the basic motor-generator torque value when the state of charge of the battery is within an allowable range;

set the allowable range of the state of charge of the battery to be smaller when the transmission is performing the shift change operation than when the transmission is performing the normal operation; and

execute a basic value shift process when the state of charge of the battery deviates from the allowable range, wherein the basic value shift process suppresses deviation of the state of charge of the battery by shifting the target engine torque from the basic engine torque value and shifting the target motor-generator torque from the basic motor-generator torque value.

2. The drive control apparatus of claim 1 wherein the controller is further configured to:

change an upper threshold value and a lower threshold value for determining whether the state of charge of the battery is within the allowable range when the transmission transitions from the normal operation to the shift change operation.

3. The drive control apparatus of claim 1, wherein the controller is further configured to:

increase the target motor-generator torque value to a larger value than the basic motor-generator torque value when the controller is executing the basic value shift process and the state of charge is deviated to an overcharge side of the allowable range.

4. The drive control apparatus of claim 1, wherein the controller is further configured to:

decrease the target motor-generator torque value to a smaller value than the basic motor-generator torque value when the controller is executing the basic value shift process and the state of charge is deviated to an overdischarge side of the allowable range.

5. The drive control apparatus of claim 1, wherein the controller is further configured to:

detect an upshift condition and a downshift condition of the transmission.

6. The drive control apparatus of claim 5, wherein the controller is further configured to:

set a lower threshold value of the allowable range to allow the motor-generator to supply the target motor-generator torque value corresponding to a decrease of the target driving torque value.

7. The drive control apparatus of claim 5, wherein the controller is further configured to:

set an upper threshold value of the allowable range to allow the motor-generator to supply the target motor-generator torque value corresponding to an increase of the target driving torque value.

8. The drive control apparatus of claim 1, wherein the controller is further configured to:

detect whether the transmission will perform the shift change operation immediately before the transmission begins performing the shift change operation.

9. The drive control apparatus of claim 1, further comprising:

an engine clutch disposed between the engine and the motor-generator, wherein the vehicle operates in an electric drive mode by only power from the motor-generator when the engine clutch is released, and wherein the vehicle operates in a hybrid drive mode by power from both of the engine and the motor-generator when the engine clutch is engaged.

10. The drive control apparatus of claim 9, wherein the controller is further configured to:

execute the basic value shift process when the vehicle is operating in the hybrid drive mode.

11. The drive control apparatus of claim 1, wherein the controller is further configured to:

calculate the basic motor-generator torque value by subtracting the basic engine torque value from the target driving torque value.

12. A drive control method for a hybrid vehicle having an engine, a motor-generator, a battery for supplying and receiving electric power to and from the motor-generator, and a transmission configured to perform a normal operation and a shift change operation, the method comprising:

detecting the normal operation and the shift change operation of the transmission;

determining a state of charge of the battery;

calculating a target driving torque value and a basic engine torque value based on a driving condition of the vehicle;

calculating a basic motor-generator torque value based on the calculated basic engine torque value and the calculated target driving torque value;

setting a target engine torque to be the basic engine torque value and setting a target motor-generator torque as the basic motor-generator torque value when the determined state of charge of the battery is within an allowable range;

setting the allowable range of the state of charge of the battery to be smaller when the transmission is performing the shift change operation than when the transmission is performing the normal operation; and

executing a basic value shift process when the state of charge of the battery is deviated from the allowable range, wherein the basic value shift process suppresses deviation of the state of charge of the battery by shifting the target engine torque from the basic engine torque value and shifting the target motor-generator torque from the basic motor-generator torque value.

13. The drive control method of claim 12, further comprising:

changing an upper threshold value and a lower threshold value for determining whether the state of charge of the battery is within the allowable range when the transmission transitions from the normal operation to the shift change operation.

14. The drive control method of claim 13, further comprising:

increasing the target motor-generator torque value to a larger value than the basic motor-generator torque value when the controller is executing the basic value shift process and the state of charge is deviated to an overcharge side of the allowable range.

15. The drive control method of claim 13, further comprising:

decreasing the target motor-generator torque value to a smaller value than the basic motor-generator torque value when the controller is executing the basic value shift process and the state of charge is deviated to an overdischarge side of the allowable range.

16. The drive control method of claim 13, further comprising:

detecting an upshift condition and a downshift condition of the transmission.

17. The drive control method of claim 16, further comprising at least one of:

setting a lower threshold value of the allowable range to allow the motor-generator to supply the target motor-generator torque value corresponding to a decrease of the target driving torque value; and

setting an upper threshold value of the allowable range to allow the motor-generator to supply the target motor-generator torque value corresponding to an increase of the target driving torque value.

18. The drive control method of claim 13, further comprising:

detecting whether the transmission will perform the shift change operation immediately before the transmission begins performing the shift change operation.

19. The drive control method of claim 13 wherein the vehicle further includes an engine clutch disposed between the engine and the motor-generator, wherein the vehicle operates in an electric drive mode by only power from the motor-generator when the engine clutch is released, and wherein the vehicle operates in a hybrid drive mode by power from both of the engine and the motor-generator when the engine clutch is engaged, the method further comprising:

executing the basic value shift process when the vehicle is operating in the hybrid drive mode.

20. The drive control method of claim 13, further comprising:

calculating the basic motor-generator torque value by subtracting the basic engine torque value from the target driving torque value.