CONTROL APPARATUS AND METHOD FOR CONTROLLING A HYBRID VEHICLE

• US 20100312427A1
• Filed: 02/27/2009
• Published: 12/09/2010
• Est. Priority Date: 03/06/2008
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ueno, Munetoshi
• Granted Patent: US 8,370,014 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 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: F02D 17/04 rendering engines inoperative or idling, e.g. caused by abnormal conditions dependent on lubricating conditions F01M1/22; dependent on cooling F01P5/14
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/045 Detection of accelerating or decelerating state detection thereof in general G01P
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A control apparatus and method of controlling a hybrid vehicle are taught herein. The vehicle selectively switches between an EV mode wherein the vehicle travels by only a driving force produced by the motor/generator when an accelerator opening is less than or equal to an engine-stop line or a HEV mode wherein the vehicle travels by at least a driving force produced by the engine the accelerator opening exceeds the engine-stop line. A transition from the HEV mode to the EV mode is executed when the accelerator opening becomes less than or equal to the engine-stop line during the HEV mode and a given delay time has expired. The delay time is set to a shorter time as an accelerator return speed decreases.

Claims

1. A control apparatus of a hybrid vehicle including an engine, a motor/generator used for vehicle propulsion and power generation, a clutch interleaved between the engine and the motor/generator for enabling and disabling torque transmission by engagement and disengagement of the clutch and an acceleration demand detection device configured to detect a driving force demand from a driver, the control apparatus comprising:

a controller configured to;

selectively switch between an EV mode, in which the vehicle travels by only a driving force produced by the motor/generator with the clutch disengaged when the driving force demand is less than or equal to an engine-stop criterion value, and an HEV mode, in which the vehicle travels by at least a driving force produced by the engine with the clutch engaged when the driving force demand is greater than the engine-stop criterion value;

set a delay time based on driving force demand change rate; and

execute a transition from the HEV mode to the EV mode when the driving force demand becomes less than or equal to the engine-stop criterion value during the HEV mode and after the delay time has expired.

2. The control apparatus according to claim 1, wherein:

the controller is further configured to decrease the delay time as the driving force demand change rate decreases.

3. The control apparatus according to claim 1, wherein:

the controller is further configured to receive a vehicle speed signal indicating the vehicle speed of the hybrid vehicle and set the delay time based on the vehicle speed.

4. The control apparatus according to claim 3, wherein:

the controller is further configured to decrease the delay time as the vehicle speed decreases.

5. The control apparatus according to claim 1, wherein the hybrid vehicle further includes a transmission interleaved between the motor/generator and drive road wheels;

and wherein;

the controller is further configured to delay the transition to the EV mode from the HEV mode during an upshift process of the transmission that continues after the driving force demand change rate becomes greater than or equal to a specified rate value at a time that the driving force demand passes through the engine-stop criterion value, until the delay time has expired and the upshift process is complete.

6. The control apparatus according to claim 1, wherein the hybrid vehicle further includes a transmission interleaved between the motor/generator and drive road wheels;

and wherein;

the controller is further configured to set the delay time to a longer time when an upshift of the transmission continues after the driving force demand change rate becomes greater than or equal to a specified value at a time that the driving force demand passes through the engine-stop criterion value.

7. The control apparatus according to claim 1, wherein:

the acceleration demand detection device comprises an accelerator opening position sensor configured to detect an accelerator opening as the driving force demand; and

the driving force demand change rate is an accelerator-pedal return speed detected by the accelerator opening sensor.

16. The control apparatus according to claim 2, wherein:

the controller is further configured to receive a vehicle speed signal indicating the vehicle speed of the hybrid vehicle and set the delay time based on the vehicle speed.

17. The control apparatus according to claim 3, wherein:

the controller is further configured to decrease the delay time as the vehicle speed decreases.

18. The control apparatus according to claim 2, wherein the hybrid vehicle further includes a transmission interleaved between the motor/generator and drive road wheels;

and wherein;

the controller is further configured to delay the transition to the EV mode from the HEV mode during an upshift process of the transmission that continues after the driving force demand change rate becomes greater than or equal to a specified rate value at a time that the driving force demand passes through the engine-stop criterion value, until the delay time has expired and the upshift process is complete.

19. The control apparatus according to claim 2, wherein the hybrid vehicle further includes a transmission interleaved between the motor/generator and drive road wheels;

and wherein;

the controller is further configured to set the delay time to a longer time when an upshift of the transmission continues after the driving force demand change rate becomes greater than or equal to a specified value at a time that the driving force demand passes through the engine-stop criterion value.

20. The control apparatus according to claim 2, wherein:

the acceleration demand detection device comprises an accelerator opening position sensor configured to detect an accelerator opening as the driving force demand; and

the driving force demand change rate is an accelerator-pedal return speed detected by the accelerator opening sensor.

8. A method of controlling a hybrid vehicle including an engine, a motor/generator used for vehicle propulsion and power generation, a clutch interleaved between the engine and the motor/generator for enabling and disabling torque transmission by engagement and disengagement of the clutch and an acceleration demand detection device configured to detect a driving force demand from a driver, the method comprising:

selectively switching between an EV mode, in which the vehicle travels by only a driving force produced by the motor/generator with the clutch disengaged when the driving force demand is less than or equal to an engine-stop criterion value, and an HEV mode, in which the vehicle travels by at least a driving force produced by the engine with the clutch engaged when the driving force demand is greater than the engine-stop criterion value;

setting a delay time based on a driving force demand change rate; and

executing a transition from the HEV mode to the EV mode when the driving force demand becomes less than or equal to the engine-stop criterion value during the HEV mode and after the delay time has expired.

9. The method according to claim 8 wherein setting the delay time based on the driving force demand change rate comprises:

decreasing the delay time as the driving force demand change rate decreases.

10. The method according to claim 8, further comprising:

receiving a vehicle speed signal indicating the vehicle speed of the hybrid vehicle; and

setting the delay time based on the vehicle speed.

11. The method according to claim 10 wherein setting the delay time based on the vehicle speed comprises:

decreasing the delay time as the vehicle speed decreases.

12. The method according to claim 8 wherein the hybrid vehicle further includes a transmission interleaved between the motor/generator and drive road wheels, the method further comprising:

delaying the transition to the EV mode from the HEV mode during an upshift process of the transmission that continues after the driving force demand change rate becomes greater than or equal to a specified rate value at a time that the driving force demand passes through the engine-stop criterion value, until the delay time has expired and the upshift process is complete.

13. The method according to claim 8 wherein the hybrid vehicle further includes a transmission, the method further comprising:

setting the delay time to a longer time when an upshift of the transmission continues after the driving force demand rate becomes greater than or equal to a specified value at a time that the driving force demand passes through the engine-stop criterion value.

14. The control method according to claim 8 wherein the acceleration demand detection device comprises an accelerator opening position sensor configured to detect an accelerator opening as the driving force demand, the method further comprising:

calculating the driving force demand change rate as an absolute value of a speed of change in the accelerator opening.

15. A control apparatus of a hybrid vehicle including an engine, a motor/generator used for vehicle propulsion and power generation, a clutch interleaved between the engine and the motor/generator for enabling and disabling torque transmission by engagement and disengagement of the clutch and an acceleration demand detection device configured to detect a driving force demand from a driver, the control apparatus comprising:

means for selectively switching between an EV mode, in which the vehicle travels by only a driving force produced by the motor/generator with the clutch disengaged when the driving force demand is less than or equal to an engine-stop criterion value, and an HEV mode, in which the vehicle travels by at least a driving force produced by the engine with the clutch engaged when the driving force demand is greater than the engine-stop criterion value;

means for setting a delay time based on driving force demand change rate; and

means for executing a transition from the HEV mode to the EV mode when the driving force demand becomes less than or equal to the engine-stop criterion value during the HEV mode and after the delay time has expired.