METHOD FOR CONTROLLING EMISSIONS

• US 20040144363A1
• Filed: 01/24/2003
• Published: 07/29/2004
• Est. Priority Date: 01/24/2003
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Ament, Frank
• Granted Patent: US 6,769,400 B1
• Time in Patent Office: Days
• US Class Current: 123/399
• CPC Class Codes: B60K 6/48 Parallel type
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 20/20 Control strategies involving selection of hybrid configuration, e.g. selection between series or parallel configuration
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method is provided for controlling emissions in a parallel hybrid motor vehicle that includes an electric propulsion system in parallel with a combustion propulsion system. In accordance with one embodiment of the invention, manifold absolute pressure (MAP) is monitored in the intake manifold of the combustion propulsion system. The electric propulsion system is engaged to reduce the MAP to a predetermined pressure, and then fueling and combustion of the combustion propulsion system are initiated only after the MAP is reduced to a pressure less than the predetermined pressure.

Claims

1. A method for controlling emissions in a parallel hybrid motor vehicle including an electric propulsion system in parallel with a combustion propulsion system, the combustion propulsion system having an intake manifold, the method comprising the steps of:

monitoring manifold absolute pressure in the intake manifold of the combustion propulsion system;

engaging the electric propulsion system to reduce the manifold absolute pressure to a predetermined pressure; and

initiating fueling and combustion of the combustion propulsion system only after the manifold absolute pressure is reduced to a pressure less than the predetermined pressure.

2. The method of claim 1 wherein the step of engaging the electric propulsion system comprises the step of powering the combustion propulsion system to achieve a predetermined combustion propulsion system RPM.

3. The method of claim 1 further comprising the step of terminating the step of engaging after the step of initiating fueling and combustion.

4. The method of claim 1 wherein the step of initiating fueling and combustion comprises the steps of:

controlling an amount of air supplied through the intake manifold to the combustion propulsion system; and

controlling an amount of fuel supplied to the combustion propulsion system.

5. The method of claim 4 wherein the step of controlling an amount of fuel injected comprises the step of controlling pulse width and frequency of injection of fuel by a fuel injector positioned to inject fuel into the combustion propulsion system.

6. The method of claim 1 further comprising the steps of:

continuing to monitor the manifold absolute pressure;

monitoring torque demand on the combustion propulsion system;

increasing the amount of fuel and the amount of air supplied to the combustion propulsion system in response to increases in monitored torque demand; and

terminating the step of increasing and reengaging the electric propulsion system in response to the manifold absolute pressure reaching the predetermined pressure.

7. The method of claim 6 further comprising the step of terminating the step of re-engaging when the combustion propulsion system is able to supply the torque demand without the manifold absolute pressure exceeding the predetermined pressure.

8. A method for controlling emissions after start-up in a parallel hybrid motor vehicle including an electric propulsion system in parallel with a combustion propulsion system, the combustion propulsion system having an intake manifold, the method comprising the steps of:

initiating propulsion of the parallel hybrid motor vehicle by the combustion propulsion system;

monitoring manifold absolute pressure in the intake manifold of the combustion propulsion system;

engaging the electric propulsion system in parallel with the combustion propulsion system in response to the manifold absolute pressure exceeding a predetermined pressure; and

maintaining the electric propulsion system engaged in parallel with the combustion propulsion system until manifold absolute pressure is reduced to the predetermined pressure.

9. The method of claim 8 further comprising the steps of:

monitoring torque demand on the parallel hybrid motor vehicle; and

limiting fueling of the combustion propulsion system in response to the manifold absolute pressure reaching a predetermined pressure before the combustion propulsion system is able to supply the torque demand.

10. The method of claim 9 further comprising the step of terminating the step of limiting fueling after a predetermined time.

11. A method for controlling emissions after start-up in a parallel hybrid motor vehicle including an electric propulsion system in parallel with a combustion propulsion system, the combustion propulsion system having an intake manifold, the method comprising the steps of:

initiating propulsion of the parallel hybrid motor vehicle by the combustion propulsion system to produce a driving torque;

monitoring manifold absolute pressure in the intake manifold of the combustion propulsion system;

monitoring torque demand on the parallel hybrid motor vehicle;

adjusting fueling of the combustion propulsion system in response to the monitored torque demand; and

in response to a sudden drop in monitored torque demand, to avoid a rapid change in the monitored manifold absolute pressure;

maintaining fueling of the combustion propulsion system at a level higher than necessary to produce a driving torque equal to the monitored torque demand; and

engaging the electric propulsion system to produce a torque counter to the driving torque.

12. The method of claim 11 wherein the parallel hybrid motor vehicle comprises a transmission and wherein the step of engaging the electric propulsion system comprises the step of coupling the electric propulsion system to the transmission.

13. The method of claim 11 wherein the step of monitoring torque demand comprises the step of monitoring signals from an accelerator pedal sensor at a control unit.

14. The method of claim 13 wherein the step of adjusting fueling comprises the step of sending a signal from the control unit to adjust a throttle flap.

15. The method of claim 14 wherein the step of maintaining fueling comprises the step of sending a further signal from the control unit to partially close the throttle flap.