Method and system for reducing operating errors in a variable value actuation system
View Patent ↗A method and control module for controlling an engine includes a lift command module that commands a first lift state after detecting an engine shut-down signal and a shut-down delay determination module that determines a shut-down delay period, that continues spark and fuel control before the shut-down delay period and that ends spark and fuel control to shut down the engine after the shut-down delay period.
1. A control system for an engine, the system comprising:
a lift command module that commands a first lift state after detecting an engine shut-down signal; and
a shut-down delay determination module that determines a shut-down delay period that continues spark and fuel control before the shut-down delay period and that ends spark and fuel control to shut down the engine after the shut-down delay period.
2. A control system as recited in claim 1 wherein an engine deactivation module generates an engine shut-down signal.
3. A control system as recited in claim 1 further comprising an accessory load control module that disables accessory loads after the lift command module commands the first lift state.
4. A control system as recited in claim 1 further comprising an accessory load control module that reduces pumping loads after the lift command module commands the first lift state.
5. A control system as recited in claim 1 wherein the shut-down delay determination module determines the shut-down delay period based on spin-down event period.
6. A control system as recited in claim 5 wherein the spin-down event period is based on at least one of engine speed, friction torque, pump torque, engine accessory torque, transmission gear, and engine cylinder count.
7. A control system as recited in claim 5 wherein the spin-down event period is based on engine speed, friction torque, pump torque, engine accessory torque, transmission gear, and engine cylinder count.
8. A control system as recited in claim 1 wherein the shut-down delay period is based on a hardware event offset period.
9. A control system as recited in claim 8 wherein the hardware event offset period comprises a difference of a minimum low-lift event period and a current low-lift event period.
10. A control system as recited in claim 1 wherein the shut-down delay period is based on spin-down event period, a hardware event offset period and a maximum low-lift to high-lift event period.
11. A method of controlling an engine, the method comprising:
detecting an engine shut-down signal;
thereafter, commanding a first lift state,
determining a shut-down delay period;
before the shut-down delay period, continuing spark and fuel control; and
after the shut-down delay period, ending spark and fuel control to shut down the engine.
12. A method as recited in claim 11 wherein detecting an engine shut-down signal comprises detecting an engine shut-down signal from an ignition system.
13. A method as recited in claim 11 wherein, after commanding a first lift state, disabling accessory loads.
14. A method as recited in claim 11 wherein, after commanding a first lift state, reducing pumping loads.
15. A method as recited in claim 11 wherein determining a shut-down delay period comprises determining the shut-down delay period based on spin-down event period.
16. A method as recited in claim 15 wherein the spin-down event period is based on at least one of engine speed, friction torque, pump torque, engine accessory torque, transmission gear, and engine cylinder count.
17. A method as recited in claim 15 wherein the spin-down event period is based on engine speed, friction torque, pump torque, engine accessory torque, transmission gear, and engine cylinder count.
18. A method as recited in claim 11 wherein determining a shut-down delay period comprises determining the shut-down delay period based on a hardware event offset period.
19. A method as recited in claim 18 wherein the hardware event offset period comprises a difference of a minimum low-lift event period and a current low-lift event period.
20. A method as recited in claim 11 wherein determining a shut-down delay period comprises determining the shut-down delay period based on spin-down event period, a hardware event offset period and a maximum low-lift to high-lift event period.