Split bank and multimode skip fire operation

Patent metadata

Field	Value
Publication number	US-9239037-B2
Application number	US-201313963759-A
Country	US
Kind code	B2
Filing date	Aug 9, 2013
Priority date	Aug 10, 2012
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

Various methods and arrangements for operating a skip fire engine control system are described. In one aspect of the invention, a distinct firing sequence is determined for each bank of working chambers that is used to operate the bank in a skip fire manner. Each firing sequence uses a different firing fraction. In another aspect of the invention, a determination is made as to whether a firing sequence should be dynamically generated or selected from a set of predefined firing sequences.

First claim

What is claimed is:

1. An engine controller arranged to operate an internal combustion engine in a skip fire manner, the engine having a plurality of working chambers organized into a plurality of banks, each bank having one or more of the working chambers, the engine controller comprising:
a firing fraction calculator arranged to generate a firing fraction that delivers a desired amount of torque; and
a firing timing determination module that is arranged to independently determine a distinct firing sequence for each bank for operating the bank in a skip fire manner such that the operation of each bank uses a different firing fraction and the banks collectively deliver the desired amount of torque.

2. An engine controller as recited in claim 1 wherein the firing fraction calculator is further arranged to determine a separate bank firing fraction for each bank.

3. An engine controller as recited in claim 1 wherein the firing timing determination module includes an interleaver that is arranged to interleave the distinct firing sequences generated for the different banks.

4. An engine controller as recited in claim 1 wherein the firing timing determination module is arranged to select a distinct firing sequence for each bank from a set of predefined firing sequences.

5. An engine controller as recited in claim 1 wherein the firing sequence for each bank is generated using a sigma delta converter.

6. An engine controller as recited in claim 1 further comprising:
a transition module that is arranged to determine whether a distinct bank firing fraction should be generated for each bank of working chambers.

7. An engine controller as recited in claim 6 further comprising:
a single firing fraction controller arranged to generate single firing fraction used to operate all banks of working chambers; and
a split bank engine firing controller arranged to generate the distinct bank firing fraction for each bank wherein the transition module is arranged to determine whether output from the single firing fraction controller or the split bank engine firing controller is used to operate the engine.

8. An engine controller as recited in claim 1 wherein the firing timing determination module is arranged to generate the firing sequence for each bank on a firing opportunity by firing opportunity basis.

9. An engine controller arranged to operate an internal combustion engine in a skip fire manner, the engine including a plurality of working chambers, the engine controller comprising:
a firing fraction calculator arranged to generate a firing fraction that delivers a desired amount of torque; and
a transition module that is arranged to determine, based at least in part on the firing fraction, whether the firing fraction will be delivered by a firing sequence selected from a set of predefined firing sequences or is generated dynamically.

10. An engine controller as recited in claim 9 wherein if the firing sequence is generated dynamically, the chosen firing sequence is generated on a firing opportunity by firing opportunity basis.

11. An engine controller as recited in claim 9 wherein if the firing sequence is generated dynamically, the chosen firing sequence is generated using an adaptive predictive algorithm.

12. An engine controller as recited in claim 11 wherein the adaptive predictive algorithm used to generate the firing sequence is a sigma delta converter.

13. An engine controller as recited in claim 9 wherein:
the engine controller further comprises a firing timing determination module that is arranged to operate the working chambers in a skip fire manner using the firing sequence wherein the firing timing determination module is further arranged to generate the firing sequence based on the determination of the transition module;
the engine includes a plurality of working chambers that are organized into a plurality of banks, each bank including a subset of the working chambers; and
the firing timing determination module is arranged to select a distinct firing sequence from the set of predefined firing sequences for each bank.

14. An engine controller as recited in claim 13 wherein:
the engine controller further comprises an interleaver that is arranged to interleave the predefined firing sequences for the plurality of banks.

15. An engine controller as recited in claim 13 wherein:
the firing fraction calculator determines a distinct firing fraction for each bank such that the banks collectively delivered the desired amount of torque.

16. An engine controller as recited in claim 13 wherein the operating of the working chambers in a skip fire manner involves deactivating at least one selected working cycle of at least one selected working chamber and firing at least one selected working cycle of at least one selected working chamber wherein individual working chambers are sometimes deactivated and sometimes fired.

17. An engine controller as recited in claim 9 further comprising:
an adaptive predictive controller (APC) that is arranged to use an adaptive predictive algorithm to generate an APC firing sequence based on the firing fraction;
a predefined sequence generator (PSG) that is arranged to choose a predefined firing sequence from a plurality of predefined firing sequences based on the firing fraction, wherein the transition module is arranged to determine whether output from the APC or the PSG is used to operate the working chambers of the engine, the transition module being arranged to select a firing sequence selected from the group consisting of the firing sequence generated by the APC and the predefined firing sequence chosen by the PSG.

18. An engine controller as recited in claim 9 further comprising a multimode controller that is arranged to adjust the firing sequence to help eliminate double firing commands generated from a transition between a predefined firing sequence and a dynamically generated firing sequence.

19. A computer readable storage medium that includes executable computer code embodied in a tangible form operable to control an internal combustion engine having a plurality of working chambers, the working chambers being organized into a plurality of banks wherein the computer readable medium includes:
executable computer code for generating a firing fraction that delivers a desired amount of torque; and
executable computer code for independently determining a distinct firing sequence for each bank for operating the bank in a skip fire manner such that the operation of each bank uses a different firing fraction and the banks collectively deliver the desired amount of torque.

20. A computer readable storage medium that includes executable computer code embodied in a tangible form operable to generate a firing sequence for operating working chambers of an engine in a skip fire manner wherein the computer readable medium includes:
executable computer code for generating a firing fraction that delivers a desired amount of torque;
executable computer code for determining a firing sequence for operating the working chambers in a skip fire manner; and
executable computer code for determining whether the firing sequence is selected from a set of predefined skip firing sequences or is generated dynamically.

Assignees

• Tula Technology Inc

Inventors

• Carlson Steven E
• Yuan Xin
• Serrano Louis J
• Switkes Joshua P
• Ghosh Biswa R
• Lo Norman C

Classifications

• F02P7/02

  of distributors · CPC title

• F02D41/1402

  Adaptive control · CPC title

• F02P5/1506 Primary

  with particular means during starting · CPC title

• F02D2200/602

  Pedal position · CPC title

• F02D41/0087

  Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123) · CPC title