US Patent No. 9,650,971


Patent No. 9,650,971
Issue Date May 16, 2017
Title Firing Fraction Management In Skip Fire Engine Control
Inventorship Mohammad R. Pirjaberi, San Jose, CA (US)
Steven E. Carlson, Oakland, CA (US)
Louis J. Serrano, Los Gatos, CA (US)
Xin Yuan, Palo Alto, CA (US)
Li-Chun Chien, Milpitas, CA (US)
Adya S. Tripathi, San Jose, CA (US)
Assignee Tula Technology, Inc., San Jose, CA (US)

Claim of US Patent No. 9,650,971

1. A skip fire engine controller for a spark ignition engine having a throttle and a camshaft having a plurality of cams,
the skip fire controller comprising:
a lookup table embodied in a computer readable media, wherein each entry in the lookup table includes a firing fraction field
that stores a firing fraction indicator indicative of a desired firing fraction associated with such entry, wherein the firing
fraction indicator does not identify any specific cylinders to fire;

a firing fraction determining unit arranged to determine a firing fraction suitable for delivering a requested engine output,
wherein the firing fraction determining unit utilizes the lookup table to determine a desired firing fraction, wherein the
firing fraction determining unit utilizes at least (i) the requested engine output, and (ii) a current engine speed as indices
to select a desired firing fraction;

a firing controller arranged to direct firings in a skip fire manner that delivers the desired firing fraction; and
a powertrain parameter adjusting module arranged to adjust at least one engine actuator that affects mass air charge (MAC)
such that the engine delivers the requested engine output at the desired firing fraction, wherein the at least one engine
actuator affects at least one of cam phase, cam lift and throttle position.