MULTI-LEVEL SKIP FIRE

摘要

In one aspect, a method for controlling operation of an internal combustion engine is described. The engine is operated in a skip fire manner such that selected skipped working cycles are skipped and selected active working cycles are fired to deliver a desired engine output. A particular level of torque output is selected for each of the fired working chambers. Various methods, arrangements and systems related to the above method are also described.

主权项

1. An engine controller for an engine including one or more working chambers, each working chamber including one or more cam-actuated intake valves, the engine controller comprising:
a firing fraction calculator arranged to determine a firing fraction suitable for delivering a desired engine torque; a firing timing determination module arranged to determine a skip fire firing sequence based on the firing fraction wherein the skip fire firing sequence indicates whether, during a selected firing opportunity, a selected working chamber is deactivated or fired and further indicates, for each fire, whether the fire generates a low torque output or a high torque output; and a firing control unit that is arranged to operate the one or more working chambers of the engine in a skip fire manner based on the firing sequence and wherein the firing control unit is further arranged to adjust air charge for each fired working chamber based on whether the firing sequence indicates a low torque output or a high torque output for the fired working chamber.