Spark retard control during cylinder transitions in a displacement on demand engine

• US 20030213467A1
• Filed: 05/17/2002
• Published: 11/20/2003
• Est. Priority Date: 05/17/2002
• 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: Rayl, Allen B., Matthews, Gregory Paul
• Granted Patent: US 6,769,403 B2
• Time in Patent Office: Days
• US Class Current: 123/406.23
• CPC Class Codes: F02D 2250/21 during a transition between engine operation modes or states
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02P 5/1504 with particular means during a transient phase, e.g. acceleration, deceleration, gear change during starting F02P5/1506
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An engine control system and method calculates spark retard during cylinder activation and deactivation for a displacement on demand engine. A torque reduction calculator calculates a torque reduction signal based on desired and measured air per cylinder. A spark retard (RTD) calculator generates a RTD signal based on the torque reduction signal.

Claims

1. An engine control system for calculating spark retard during cylinder deactivation for a displacement on demand engine, comprising:

a torque reduction calculator that calculates a torque reduction signal based on desired and measured air per cylinder; and

a spark retard (RTD) calculator that generates a RTD signal based on said torque reduction signal.

2. The engine control system of claim 1 wherein said RTD signal is a negative offset from a minimum best torque (MBT).

3. The engine control system of claim 1 further comprising a final RTD calculator that generates a final RTD signal based on said RTD signal, an MBT signal and a spark advance (SA) signal.

4. The engine control system of claim 3 wherein said final spark retard=−

(MBT+RTD)−

(MBT−

SA).

5. The engine control system of claim 1 further comprising:

a cylinder deactivation enable circuit for generating a cylinder deactivation enable signal; and

a selector for selecting one of a desired deactivated air per cylinder and an activated air per cylinder based on said cylinder deactivation enable signal.

6. An engine control system for calculating spark retard during cylinder activation for a displacement on demand engine, comprising:

a torque reduction calculator that calculates a torque reduction signal based on desired and measured air per cylinder;

a spark retard (RTD) calculator that generates a RTD signal based on said torque reduction signal.

7. The engine control system of claim 6 further comprising:

an activation gain circuit for providing a gain signal;

a multiplier for generating a product by multiplying said gain signal by said torque reduction signal, wherein said product is input to said RTD calculator.

8. The engine control system of claim 7 wherein said RTD signal is a negative offset from a minimum best torque (MBT).

9. The engine control system of claim 6 further comprising a final RTD calculator that generates a final RTD signal based on said RTD signal, an MBT signal and a spark advance (SA) signal.

10. The engine control system of claim 9 wherein said final spark retard=−

(MBT+RTD)−

(MBT−

SA).

11. The engine control system of claim 9 further comprising:

a cylinder reactivation circuit that generates a cylinder reactivation enable signal; and

a multiplier that generates a second product of said cylinder reactivation enable signal and said final RTD signal.

22. The engine control system of claim 9 further comprising:

generates a cylinder reactivation enable signal; and

a multiplier that generates a second product of said cylinder reactivation enable signal and said final RTD signal.

12. A method for calculating spark retard during cylinder deactivation for a displacement on demand engine, comprising:

calculates a torque reduction signal based on desired and measured air per cylinder; and

generates a spark retard (RTD) signal based on said torque reduction signal.

13. The method of claim 12 wherein said RTD signal is a negative offset from a minimum best torque (MBT).

14. The method of claim 12 further comprising generating a final RTD signal based on said RTD signal, an MBT signal and a spark advance (SA) signal.

15. The method of claim 14 wherein said final spark retard=−

(MBT+RTD)−

(MBT−

SA).

16. The method of claim 12 further comprising:

generating a cylinder deactivation enable signal; and

selecting one of a desired deactivated air per cylinder and a desired activated air per cylinder based on said cylinder deactivation enable signal.

17. A method for calculating spark retard during cylinder activation for a displacement on demand engine, comprising:

calculating a torque reduction signal based on desired and measured air per cylinder;

generating a RTD signal based on said torque reduction signal.

18. The method of claim 17 further comprising:

providing an activation gain signal;

generating a product by multiplying said gain signal by said torque reduction signal, wherein said product is input to said RTD calculator.

19. The engine control system of claim 18 wherein said RTD signal is a negative offset from a minimum best torque (MBT).

20. The engine control system of claim 17 further comprising generates a final RTD signal based on said RTD signal, an MBT signal and a spark advance (SA) signal.

21. The engine control system of claim 20 wherein said final spark retard=−

(MBT+RTD)−

(MBT−

SA).