System and method for controlling spark timing when cylinders of an engine are deactivated to reduce noise and vibration
View Patent ↗A system according to the principles of the present disclosure includes a cylinder activation module and a spark timing module. The cylinder activation module selectively deactivates and reactivates a cylinder of an engine based on a driver torque request. When the cylinder is deactivated, the spark timing module selectively increases an amount by which spark timing of at least one active cylinder of the engine is retarded based on noise and vibration generated by the engine when the cylinder is deactivated.
1. A system comprising:
a cylinder activation module that selectively deactivates and reactivates a cylinder of an engine based on a driver torque request; and
a spark timing module that, when the cylinder is deactivated for multiple engine cycles, selectively increases an amount of spark retard for at least one other cylinder of the engine that is active based on noise and vibration generated by the engine when the cylinder is deactivated.
2. The system of claim 1 wherein:
the spark timing module selectively increases the amount of spark retard for M of N active cylinders of the engine when the cylinder is deactivated; and
M is less than N.
3. The system of claim 1 wherein the spark timing module selectively increases the amount of spark retard for all active cylinders of the engine when the cylinder is deactivated.
4. The system of claim 3 wherein:
the cylinder activation module selectively reactivates N cylinders of the engine when the amount of spark retard for all of the active cylinders is increased; and
N is based on the driver torque request.
5. The system of claim 1 further comprising a noise and vibration (N&V) prediction module that predicts the noise and vibration generated by the engine when the cylinder is deactivated.
6. The system of claim 5 wherein the N&V prediction module predicts the noise and vibration generated by the engine based on a predetermined relationship between an input frequency at a powertrain mount and an output frequency at a driver interface component.
7. The system of claim 5 wherein the N&V prediction module predicts the noise and vibration generated by the engine based on a firing sequence of the engine and spark timing of active cylinders of the engine.
8. The system of claim 1 further comprising a firing sequence module that adjusts a firing sequence of the engine between consecutive engine cycles to change a quantity of active cylinders in the engine.
9. The system of claim 5 wherein:
the N&V prediction module applies a band-pass filter to feedforward data and feedback data associated with torque output of the engine; and
the spark timing module adjusts the spark timing of the at least one active cylinder based on the filtered data.
10. The system of claim 9 wherein:
the feedforward data includes the driver torque request; and
the feedback data includes crankshaft speed.
11. A method comprising:
selectively deactivating and reactivating a cylinder of an engine based on a driver torque request; and
when the cylinder is deactivated for multiple engine cycles, selectively increasing an amount of spark retard for at least one other cylinder of the engine that is active based on noise and vibration generated by the engine when the cylinder is deactivated.
12. The method of claim 11 further comprising selectively increasing the amount of spark retard for M of N active cylinders of the engine when the cylinder is deactivated, wherein M is less than N.
13. The method of claim 11 further comprising selectively increasing the amount of spark retard for all active cylinders of the engine when the cylinder is deactivated.
14. The method of claim 13 further comprising selectively reactivating N cylinders of the engine when the amount of spark retard for all of the active cylinders is increased, wherein N is based on the driver torque request.
15. The method of claim 11 further comprising predicting the noise and vibration generated by the engine when the cylinder is deactivated.
16. The method of claim 15 further comprising predicting the noise and vibration generated by the engine based on a predetermined relationship between an input frequency at a powertrain mount and an output frequency at a driver interface component.
17. The method of claim 15 further comprising predicting the noise and vibration generated by the engine based on a firing sequence of the engine and spark timing of active cylinders of the engine.
18. The method of claim 11 further comprising adjusting a firing sequence of the engine between consecutive engine cycles to change a quantity of active cylinders in the engine.
19. The method of claim 15 further comprising:
applying a band-pass filter to feedforward data and feedback data associated with torque output of the engine; and
adjusting the spark timing of the at least one active cylinder based on the filtered data.
20. The method of claim 19 wherein:
the feedforward data includes the driver torque request; and
the feedback data includes crankshaft speed.