Firing fraction management in skip fire engine control

摘要

In various described embodiments skip fire control is used to deliver a desired engine output. A controller determines a skip fire firing fraction and (as appropriate) associated engine settings that are suitable for delivering a requested output. In one aspect, the firing fraction is selected from a set of available firing fractions, with the set of available firing fractions varying as a function of engine speed such that more firing fractions are available at higher engine speeds than at lower engine speeds. The controller then direct firings in a skip fire manner that delivers the selected fraction of firings.

主权项

1. A skip fire engine controller comprising:
a firing fraction determining unit arranged to determine an operational firing fraction and associated engine settings for delivering a desired engine output, wherein the firing fraction determining unit is arranged to select the firing fraction from a set of available firing fractions, wherein the set of available firing fractions varies as a function of engine speed such that more firing fractions are available at higher engine speeds than at lower engine speeds; and a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction.