Coordination of vehicle actuators during firing fraction transitions

A method of controlling an engine to deliver a requested engine output, the method comprising:

• while the engine is operating at a first effective firing fraction having an associated first cam phase, determining a desired second effective firing fraction and an associated second cam phase, the second cam phase being different than the first cam phase;
• initiating a transition from the first cam phase to the second cam phase;
• after an actual cam phase is at or within a predetermined range of the second cam phase transitioning to the second effective firing fraction, wherein transition to the second effective firing fraction is initiated only after the actual cam phase is at or within the predetermined range of the second cam phase;
• and
• directing operation of the engine during the transitions to deliver the requested engine output, whereby an actual commanded effective firing fraction gradually changes over a course of the transitions from the first effective firing fraction to the second effective firing fraction, and
• wherein operating the engine at at least one of the first and second effective firing fractions involves operating the engine in a multi-level skip fire or multi-charge level operating mode.

An engine controller arranged to direct dynamic firing level modulation operation of an engine, the engine controller being configured to:

• (a) direct operation of the engine at a first effective firing fraction and a first cam phase;
• (b) while the engine is operating at the first effective firing fraction and the first cam phase, determine a requested effective firing fraction that is different than the first effective firing fraction, the requested effective firing fraction being a second effective firing fraction having an associated second cam phase, the second cam phase being different than the first cam phase;
• (c) select an intermediate effective firing fraction that is between the first and second effective firing fractions, the intermediate effective firing fraction having an associated intermediate cam phase;
• (d) identify the selected intermediate effective firing fraction as a target effective firing fraction and the intermediate cam phase as a target cam phase;
• (e) initiate a transition from the first cam phase to one of the second cam phase or the target cam phase;
• (f) after an actual cam phase is at or within a predetermined range of the target cam phase transition to the target effective firing fraction;
• (g) when the target effective firing fraction is not the second effective firing fraction, select a next effective firing fraction having an associated next cam phase and set the target effective firing fraction to be the next effective firing fraction and set the target cam phase to be the next cam phase and cause the cam phase to transition towards the next cam phase or to transition towards or continue transitioning towards the second cam phase;
• and
• (h) iteratively repeat (f) and (g) until the second cam phase and second effective firing fraction are reached;
• and
• (i) direct operation of the engine during the transitions to deliver the requested engine output, whereby an actual commanded effective firing fraction changes over a course of the transitions, and
• wherein operating the engine at at least one of the first, second and intermediate effective firing fractions involves operating the engine in a multi-level skip fire or multi-charge level operating mode.

An engine controller arranged to direct dynamic firing level modulation operation of an engine, the engine controller being configured to:

• direct operation of the engine at a first effective firing fraction and a first cam phase;
• while the engine is operating at the first effective firing fraction and the first cam phase, determine a desired second effective firing fraction and an associated second cam phase, the second cam phase being different than the first cam phase;
• initiate a transition from the first cam phase to the second cam phase;
• after an actual cam phase is at or within a predetermined range of the second cam phase direct a transition to the second effective firing fraction, wherein the transition to the second effective firing fraction is initiated only after the actual cam phase is at or within the predetermined range of the second cam phase;
• and
• direct operation of the engine during the cam phase and effective firing fraction transitions to deliver the requested engine output, whereby an actual commanded effective firing fraction changes over a course of the transitions from the first effective firing fraction to the second effective firing fraction, and
• wherein operating the engine at at least one of the first and second effective firing fractions involves operating the engine in a multi-level skip fire or multi-charge level operating mode.