US Pat. No. 9,512,794

NOISE, VIBRATION AND HARSHNESS REDUCTION IN A SKIP FIRE ENGINE CONTROL SYSTEM

Tula Technology, Inc., S...

1. A powertrain controller for operating an internal combustion engine in a skip fire manner using an operational firing fraction
that is fuel efficient and has acceptable noise, vibration and harshness (NVH) characteristics, the powertrain controller
comprising:
a firing fraction calculator arranged to generate an operational firing fraction to deliver a desired engine torque;
a firing determination timing module that is arranged to generate a firing sequence used to operate the engine in a skip fire
manner, the skip fire firing sequence being based on the operational firing fraction; and

an NVH reduction module that is arranged to determine a smoothing torque that is applied to a powertrain by an energy storage/release
device wherein the smoothing torque is arranged to at least partially cancel out a variation in torque generated by the skip
fire firing sequence, thereby reducing NVH that would otherwise be generated by the skip fire firing sequence.

US Pat. No. 9,650,923

SYSTEM AND METHOD FOR SAFE VALVE ACTIVATION IN A DYNAMIC SKIP FIRING ENGINE

Tula Technology, Inc., S...

1. An internal combustion engine comprising:
an engine controller arranged to operate the engine in a skip fire mode;
at least one selectively activatable cylinder, each selectively activatable cylinder having an associated intake valve and
an associated exhaust valve, wherein the exhaust valve associated with each selectively activatable cylinder can be selectively
opened or held closed during a selected working cycle to help facilitate deactivating the cylinder during skipped working
cycles that occur during skip fire operation of the engine such that air is not pumped through the cylinder during the skipped
working cycles; and

a valve control system arranged to ensure that during skip fire operation, the intake valve does not open when the selectively
activatable cylinder contains high pressure combustion gases, the valve control system including an exhaust valve motion verification
module arranged to detect opening of the exhaust valve to vent combustion gases.

US Pat. No. 9,581,098

ENGINE DIAGNOSTICS WITH SKIP FIRE CONTROL

Tula Technology, Inc., S...

1. A method of operating an internal combustion engine having a plurality of cylinder banks, each bank including a plurality
of cylinders, the method comprising:
operating the engine in a skip fire operational mode that utilizes most evenly spaced firings;
while operating in the skip fire operational mode, identifying a period in which a single one of the cylinders in a first
cylinder bank is isolated as the only firing cylinder in the first cylinder bank; and

conducting a diagnosis of the isolated cylinder during the identified period, wherein the diagnosis conducted on the isolated
cylinder is not conducted on the isolated cylinder when such cylinder is not isolated.

US Pat. No. 9,291,106

CAM PHASER CONTROL

TULA TECHNOLOGY, INC., S...

1. A method of controlling the phase of an adjustable phase camshaft relative to a crankshaft of an engine, wherein the adjustable
phase camshaft is utilized to actuate at least one engine valve, the method comprising utilizing knowledge of at least one
of:
(i) firing events in a skip fire firing sequence, and
(ii) dynamically determined valve actuation events,in the control of a cam phase adjustment device in a manner that maintains the phase of the adjustable phase camshaft more
stable at a consistent commanded camshaft position through transitory variations in torque applied to the adjustable phase
camshaft by the actuation of the at least one engine valve than would occur without such control.

US Pat. No. 9,200,575

MANAGING ENGINE FIRING PATTERNS AND PATTERN TRANSITIONS DURING SKIP FIRE ENGINE OPERATION

Tula Technology, Inc., S...

1. A method of managing a transition between a first operational firing fraction and a second operational firing fraction
during operation of an engine in a skip fire operational mode, the first firing fraction having an associated first repeating
firing sequence and the second firing fraction having an associated second repeating firing sequence, the method comprising:
identifying a firing sequence segment of a designated length that is shared by the first and second firing fractions, wherein
the shared firing sequence segment is a set of individual working chamber firing decisions that is the same in the first and
second repeating firing sequences, the first and second firing fractions being different; and

transitioning from the first to the second firing fraction in conjunction with the execution of the shared firing sequence
segment, whereby the firing fraction entering the shared firing sequence is the first firing fraction and the firing fraction
exiting the shared sequence is the second firing fraction.

US Pat. No. 9,422,880

TORQUE CONVERTER CLUTCH LOCKUP DURING SKIP-FIRE OPERATION

Tula Technology, Inc., S...

1. A method of operating a vehicle having an internal combustion engine and a powertrain, wherein the powertrain includes
an engine-decoupling friction interface and has one or more resonant frequencies of concern, the method comprising:
operating the engine in a skip-fire manner to supply motive power to move the vehicle;
transferring the engine motive power through the friction interface;
while the engine is operating in the skip-fine manner, automatically determining whether current skip-fire operating conditions
are suitable for locking-up the friction interface, wherein the friction interface lock-up determination is based at least
in part on current engine speed and current skip-fire firing fraction and is arranged to ensure that a current combustion
frequency does not incite any of the one or more resonant frequencies of concern; and

locking-up the friction interface during operation in the skip-fire manner when it is determined that current skip fire operating
conditions are suitable for locking-up the friction interface.

US Pat. No. 9,581,097

DETERMINATION OF A HIGH PRESSURE EXHAUST SPRING IN A CYLINDER OF AN INTERNAL COMBUSTION ENGINE

Tula Technology, Inc., S...

1. A method of determining whether a high pressure exhaust spring is present in a cylinder of a spark ignition, internal combustion
engine having a reciprocating piston, the method comprising:
measuring at least one electrical property of a spark gap in a cylinder; and
based on the electrical property measurement, determining whether a high pressure exhaust spring is present in the cylinder.

US Pat. No. 9,273,643

CONTROL OF MANIFOLD VACUUM IN SKIP FIRE OPERATION

Tula Technology, Inc., S...

1. A method of selectively reducing intake manifold pressure in a skip fire engine control system to help purge a fuel vapor
canister, reduce pressure within a brake vacuum booster reservoir or vent gas from a crankcase interior, the method comprising:
operating an engine in a skip fire manner to generate a desired torque level using a throttle set at a substantially open
position;

further closing the throttle to reduce the intake manifold pressure in order to perform a manifold vacuum-related process
selected from the group consisting of 1) purging the fuel vapor canister; 2) reducing pressure within a brake vacuum booster
reservoir; and 3) venting gas from the crankcase interior;

increasing an engine firing fraction to help maintain the desired torque level; and
after the manifold vacuum-related process has been performed, returning the throttle to the substantially open position and
decreasing the firing fraction.

US Pat. No. 9,267,454

DRIVE TRAIN SLIP FOR VIBRATION MITIGATION DURING SKIP FIRE OPERATION

Tula Technology, Inc., S...

1. A method of mitigating power train vibration during skip fire operation of an engine, the method comprising:
operating an engine in a skip fire operational mode; and
for each firing opportunity in a sequence of firing opportunities that occur during the skip fire operation of the engine,
determining a drive train component slip dynamically on an individual firing opportunity by firing opportunity basis, wherein
the slip of the drive train component associated with each firing opportunity is based at least in part upon a skip/fire decision
associated with such firing opportunity; and

modulating the slip of the drive train component in accordance with the determined drive train component slip, whereby in
at least some circumstances, the slip of the drive train will be adjusted both up and down for different firing opportunities
within a single engine cycle while operating in the skip fire mode.

US Pat. No. 9,541,050

INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY

Tula Technology, Inc., S...

1. An engine controller suitable for use with an internal combustion engine having a plurality of cylinders, each cylinder
having an associated piston and being arranged to operate in a succession of working cycles having at least four strokes,
the engine controller comprising:
a skip fire controller arranged to direct operation of the engine in a skip fire mode that causes selected active working
cycles to be fired and selected skipped working cycles not to be fired, the skip fire controller being arranged to make firing
decisions, wherein the firing decisions are made on a working cycle by working cycle basis; and

wherein the engine controller is arranged to deactivate skipped working chambers during selected skipped working cycles to
thereby prevent pumping air through the skipped working chambers during the selected skipped working cycles.

US Pat. No. 9,387,849

IMPLEMENTING SKIP FIRE WITH START/STOP FEATURE

Tula Technology, Inc., S...

1. A method for implementing a start/stop feature in a skip fire engine control system, the skip fire engine control system
including an internal combustion engine having a plurality of working chambers, the method comprising:
implementing a stop/start feature that involves automatically turning off the engine under selected circumstances during a
drive cycle;

determining that the turned off engine should be restarted; and
during an engine startup period, operating the engine in a skip fire manner until a desired engine speed is reached wherein
the skip fire operation of the engine involves firing at least one selected working cycle of at least one selected working
chamber and deactivating at least one selected working cycle of at least one selected working chamber such that air does not
pass through the at least one working chamber during the at least one deactivated working cycle wherein the working chambers
are arranged to be hydraulically deactivated using oil pressure and the oil pressure is raised before firing any working chambers
so that skipped working chambers can be deactivated.

US Pat. No. 9,650,971

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

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.

US Pat. No. 9,328,672

ENGINE BRAKING CONTROLLER

Tula Technology, Inc., S...

1. A method of controlling the amount of engine braking provided by an engine having at least one working chamber, the method
comprising:
determining a desired amount of engine braking; and
operating the engine in a skip cylinder engine braking mode that substantially delivers the desired amount of engine braking,
wherein in the skip cylinder engine braking mode, selected working cycles of at least one selected working chamber are deactivated
and other selected working cycles of the at least one selected working chamber are operated in a braking mode such that at
least one working chamber is sometimes deactivated and sometimes operated in the braking mode, and wherein at least some of
the working cycles operated in a braking mode, fuel is delivered to the working chambers operated in the braking mode, the
working chambers operated in the braking mode are fired and the fired working chambers in the braking mode each generate a
net negative torque.

US Pat. No. 9,200,587

LOOK-UP TABLE BASED SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

1. A skip fire engine controller comprising:
a look-up table embodied in a computer readable media, the look-up table having a multiplicity of entries and wherein at least
some of the entries include a first element that indicates a firing decision and a second element that includes indexing information
that is at least sometimes used to determine a relevant lookup table entry for a next firing decision; and

a firing controller arranged to direct firings in a skip fire manner that delivers a desired engine output, wherein the firing
controller utilizes the look-up table to determine when firings are appropriate.

US Pat. No. 9,120,478

TRANSITORY TORQUE MODIFICATIONS USING SKIP FIRE CONTROL

Tula Technology, Inc., S...

1. An engine controller arranged to:
direct operation of an engine to deliver a requested engine output;
direct skip fire operation of the engine during a transmission shift event to deliver a transitory engine output that is significantly
less than the requested engine output, wherein the difference between the transitory engine output and the requested engine
output is provided in significant part by a difference in a percentage of working cycles that are fired during the transmission
shift as compared to the percentage of working cycles that are fired immediately prior to the transmission shift; and

restore the engine output to the requested engine output after the transmission shift event is completed.

US Pat. No. 9,212,610

ENGINE DIAGNOSTICS WITH SKIP FIRE CONTROL

Tula Technology, Inc., S...

1. A method comprising:
operating a engine in a skip fire manner to deliver a desired engine output; identifying a time period during skip fire operation
that is suitable for initiating or performing a selected engine diagnosis, wherein the selected engine diagnosis utilizes
a sensor that is associated with a group of cylinders and the identified time period is one selected from the group consisting
of (i) a time period in which a single first cylinder in the group of cylinders is fired a plurality of times in isolation
relative to the sensor used in the diagnosis, and (ii) a time period in which no cylinder in a first bank of cylinders associated
with the sensor used in the diagnosis is fired over the course of at least one engine cycle while at least one other cylinder
not associated with the first bank of cylinder is fired; and

conducting or initiating the selected engine diagnosis during the identified time period while the engine is operated in a
skip fire manner to deliver the desired engine output.

US Pat. No. 9,086,020

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

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.

US Pat. No. 9,528,446

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

1. A skip fire engine controller for determining which working cycles to skip and which working cycles to fire during skip
fire operation of an internal combustion engine having a plurality of working chambers, the skip fire engine controller comprising:
a firing fraction determining unit arranged to determine a firing fraction suitable for delivering a desired engine output,
wherein the firing fraction determining unit is arranged and constrained to determine an operational firing fraction that
has an associated repeating firing cycle length that is assured to repeat at least a designated number of times per second
at the current engine speed; and

a firing controller arranged to direct firings in a skip fire manner that delivers the operational firing fraction, the firing
controller being arranged to make firing decisions on a firing opportunity by firing opportunity basis; and

wherein the firing controller includes an accumulator that tracks a relative portion of a firing that has been requested but
not yet directed by the firing controller, whereby the accumulator helps smooth transitions between different firing fractions.

US Pat. No. 9,399,963

MISFIRE DETECTION SYSTEM

Tula Technology, Inc., S...

1. A method for detecting misfire in a skip fire engine control system, the method comprising:
assigning a window to a target firing opportunity for a target working chamber;
attempting to fire the target working chamber during the target firing opportunity;
measuring a change in an engine parameter during the window;
determining whether a firing opportunity before the target firing opportunity is a skip or a fire and whether a firing opportunity
after the target firing opportunity is a skip or a fire; and

determining whether the target working chamber misfired based at least in part on the skip or fire determination from before
and after the target firing opportunity and the measured change in the engine parameter.

US Pat. No. 9,476,373

MULTI-LEVEL SKIP FIRE

Tula Technology, Inc., S...

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.

US Pat. No. 9,239,037

SPLIT BANK AND MULTIMODE SKIP FIRE OPERATION

Tula Technology, Inc., S...

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.

US Pat. No. 9,494,088

AVERAGING FILTER FOR SKIP FIRE ENGINE OPERATION

Tula Technology, Inc., S...

1. A method comprising:
operating an engine in an operating mode having a plurality of different effective firing fractions;
measuring an engine operating parameter during the operation of the engine at a current firing fraction having an effective
firing fraction of less than one;

averaging the measured operating parameter over a period that is based on and varies with changes in at least one of (i) a
denominator of the current firing fraction, and (ii) a repeating firing sequence length associated with the current firing
fraction; and

using the averaged measured operating parameter as the value of the measured operating parameter in an engine control calculation
or operation during the operation of the engine.

US Pat. No. 9,086,024

INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY

Tula Technology, Inc., S...

1. A method of controlling the operation of a vehicle that includes a continuously variable transmission and an engine having
at least one least one working chamber, each working chamber being generally arranged to operate in a succession of working
cycles, the method comprising:
operating the engine in a skip fire mode that skips the firing of selected skipped working cycles and fires selected active
working cycles, wherein an amount of air and fuel that is substantially optimized for fuel efficiency is delivered to the
working chambers during the active working cycles; and

controlling the continuously variable transmission such that during operation in the skip fire mode the engine operates at
a rotational speed that is substantially optimized for fuel efficiency; and

whereby when the engine is operated in the skip fire mode, a majority of the active working cycles are operated in a condition
that is substantially optimized for fuel efficiency.

US Pat. No. 10,100,754

DYNAMICALLY VARYING AN AMOUNT OF SLIPPAGE OF A TORQUE CONVERTER CLUTCH PROVIDED BETWEEN AN ENGINE AND A TRANSMISSION OF A VEHICLE

Tula Technology, Inc., S...

1. A system for dynamically varying an amount of slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission input shaft of a vehicle, the system comprising:a controller for varying a slippage output signal applied to the TCC in order to vary the amount of slippage between the engine rotation rate and the transmission input shaft, the amount of slippage varying based on one or more measured non-powertrain factors that are sources of non-powertrain noise and vibration.

US Pat. No. 9,482,202

TORQUE COMPENSATION FOR DETONATION

Tula Technology, Inc., S...

1. A method for mitigating detonation and managing torque in a spark ignition internal combustion engine operated in a skip
fire manner, the engine having a plurality of working chambers, the method comprising:
operating the working chambers of the engine in a skip fire manner to deliver a desired torque based on a firing fraction;
detecting one or more detonations in a working chamber of the engine;
in response to the detection of the one or more detonations, retarding spark timing for one or more of the working chambers;
automatically increasing the firing fraction used to operate the engine such that the increased firing fraction helps compensate
for torque lost due to the retarding of the spark timing; and

operating the working chambers of the engine in a skip fire manner based on the increased firing fraction to deliver the desired
torque.

US Pat. No. 10,072,592

MULTI-LEVEL SKIP FIRE

Tula Technology, Inc., S...

1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers to deliver a desired output, wherein each working chamber has at least one intake valve and at least one exhaust valve, the method comprising:operating the engine in a dynamic firing level modulation mode that causes selected low working cycles to be fired at a low torque output and selected high working cycles to be fired at a high torque output, wherein decisions whether to fire each working cycle at a high or low torque output are dynamically determined during operation of the engine on an individual firing opportunity by firing opportunity basis; and
adjusting an air charge for each fired working cycle based on whether the high or low torque output was selected for such fired working cycle.

US Pat. No. 9,726,094

SYSTEM FOR MANAGING CATALYTIC CONVERTER TEMPERATURE

Tula Technology, Inc., S...

1. An engine controller for operating an internal combustion engine in a skip fire manner, the engine controller including
a plurality of working chambers, the engine controller comprising:
a catalytic monitor arranged to obtain data relating to a temperature of a catalytic converter wherein the catalytic converter
temperature data is obtained from one selected from the group consisting of a catalytic converter temperature model and a
sensed catalytic converter temperature; and

a firing timing determination unit that is arranged to determine a firing sequence for operating the working chambers of the
engine in a skip fire manner wherein the firing sequence is generated at least in part based on the catalytic converter temperature
data; and

wherein the firing timing determination unit is arranged to perform firings only in a first subset of the working chambers
and not in a second subset of the working chambers during an engine startup period.

US Pat. No. 9,175,613

SYSTEM AND METHOD FOR SAFE VALVE ACTIVATION IN A DYNAMIC SKIP FIRING ENGINE

Tula Technology, Inc., S...

1. A method of controlling the operation of an internal combustion engine having at least one cylinder, each cylinder having
an associated intake valve and an associated exhaust valve, the method comprising:
directing skip fire operation of the engine;
determining whether an exhaust valve actuation failure has occurred in which the exhaust valve associated with a selected
cylinder fails to open properly during a selected working cycle during the skip fire operation of the engine; and

when it is determined that an exhaust valve actuation failure has occurred, deactivating the intake valve associated with
the selected cylinder during a subsequent working cycle in which the intake valve would otherwise have been actuated in response
to the detection of the exhaust valve actuation failure.

US Pat. No. 9,399,964

MULTI-LEVEL SKIP FIRE

Tula Technology, Inc., S...

1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers to deliver
a desired output, wherein each working chamber has at least one intake valve that is cam-actuated and at least one exhaust
valve, the method comprising:
operating the engine in a skip fire manner that skips selected skipped working cycles and fires selected active working cycles
to deliver a desired engine output, wherein decisions whether to fire or skip each working cycle are dynamically determined
during operation of the engine on a firing opportunity by firing opportunity basis; and

selecting a high or low torque output on the fired working chambers wherein decisions whether to use a high or low torque
output are dynamically determined during operation of the engine on a firing opportunity by firing opportunity basis; and

adjusting air charge for the fired working chambers based on whether the high or low torque output was selected on the fired
working chambers.

US Pat. No. 9,562,470

VALVE FAULT DETECTION

Tula Technology, Inc., S...

1. A method comprising:
operating an engine having a plurality of cylinders in a skip fire mode, the engine including at least one cylinder, each
cylinder having at least one associated intake valve and one associated exhaust valve;

estimating an expected net torque during a selected operating window utilizing a torque model, wherein the torque model considers
an expected torque contribution from each of the cylinders and accounts for the effects of specific skip fire firing decisions
that affect the expected torque contribution from each cylinder during the selected operating window;

directly or indirectly measuring a parameter indicative of actual engine torque during the selected operating window;
determining whether a valve actuation fault has occurred based at least in part on a comparison of the measured parameter
to an expected parameter value that is based at least in part on the expected net torque, wherein the determination is made
within one engine cycle of the occurrence of the valve actuation fault; and

when it is determined that a valve actuation fault has occurred, performing at least one of (a) altering an aspect of control
of the engine while the engine is operating in the skip fire mode in response to said determination; and (b) recording the
detection of the valve actuation fault in a diagnostics system.

US Pat. No. 9,790,867

DECELERATION CYLINDER CUT-OFF

Tula Technology, Inc., S...

1. A method of operating an engine having a crankshaft, an intake manifold and a plurality of working chambers, the method
comprising, during operation of the engine:
deactivating all of the working chambers in response to a no engine torque request such that none of the working chambers
are fired and no air is pumped through the working chambers as the crankshaft rotates;

subsequent to the deactivation of all of the working chambers, reactivating at least some of the working chambers to pump
air through the reactivated cylinders during a series of air pumping working cycles to thereby reduce the pressure in the
intake manifold, wherein the reactivated cylinders are not fired during the air pumping working cycles; and

firing at least some working cycles only after at least a plurality of the air pumping working cycles have been executed to
cause the engine to deliver the requested torque, whereby the intake manifold pressure at the time that the first fired working
cycle after the deactivation of all of the working chambers begins, is lower than the intake manifold pressure immediately
before the first of the series of air pumping working cycles.

US Pat. No. 9,777,658

SKIP FIRE TRANSITION CONTROL

Tula Technology, Inc., S...

1. A method of controlling the transition of an engine between different firing fractions, the method comprising:
while the engine is operating at a first firing fraction using a first value for an operating parameter that affects working
chamber air charge, determining a target value for the operating parameter that is different than the first value, and a target
firing fraction selected to deliver a requested engine output;

transitioning from the first firing fraction to the target firing fraction;
during the transition, determining a feed forward adjusted firing fraction that at least partially compensates for engine
dynamics that occur during the change from the initial value for the operating parameter to the target value for the operating
parameter, wherein the feed forward adjusted firing fraction changes over the course of the transition;

during the transition, determining a firing fraction correction factor indicative of a difference between an actual engine
output and the requested engine output, wherein the firing fraction correction factor potentially varies over the course of
the transition;

determining a commanded firing fraction during the transition that combines the firing fraction correction factor with the
feed forward adjusted firing fraction; and

directing skip fire operation of the engine utilizing the commanded firing fraction during the transition, whereby the commanded
firing fraction changes over the course of the transition.

US Pat. No. 9,725,082

IMPLEMENTING SKIP FIRE WITH START/STOP FEATURE

Tula Technology, Inc., S...

1. A method for implementing a start/stop feature in a skip fire engine control system, the skip fire engine control system
including an internal combustion engine having a plurality of working chambers, the method comprising:
implementing a stop/start feature that involves automatically turning off the engine under selected circumstances during a
drive cycle;

determining that the turned off engine should be restarted; and
during an engine startup period, operating the engine in a skip fire manner until a target engine speed is reached wherein
the skip fire operation of the engine involves firing at least one selected working cycle of at least one selected working
chamber and deactivating at least one selected working cycle of at least one selected working chamber such that air does not
pass through the at least one working chamber during the at least one deactivated working cycle.

US Pat. No. 9,745,905

SKIP FIRE TRANSITION CONTROL

Tula Technology, Inc., S...

1. A method of controlling the transition of an engine between different firing fractions, the method comprising:
while the engine is operating at a first firing fraction, determining a second target firing fraction that is different than
the first firing fraction; and

transitioning from the first firing fraction to the target firing fraction by gradually altering a commanded firing fraction
from the first firing fraction to the second firing fraction, wherein the commanded firing fraction is altered each firing
opportunity.

US Pat. No. 9,689,327

MULTI-LEVEL SKIP FIRE

Tula Technology, Inc., S...

1. An engine controller for an engine including a plurality of working chambers, each working chamber including at least one
cam-actuated intake valve, the engine controller comprising:
a firing fraction calculator arranged to determine a firing fraction suitable for delivering a desired 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 working chambers in a skip fire manner based on the firing sequence.

US Pat. No. 10,060,368

ENGINE TORQUE SMOOTHING

Tula Technology, Inc., S...

1. A method of estimating a torque profile of an engine having a plurality of working chambers during operation of the engine, the engine being arranged to operate in a sequence of firing opportunities, each firing opportunity having a corresponding working cycle having a corresponding operational state, each operational state having an associated normalized torque profile, the method comprising:determining or selecting a normalized torque profile corresponding to an operational state of a selected working chamber during a selected working cycle;
determining a torque profile for the selected working chamber based at least in part on scaling the normalized torque profile corresponding to the selected working chamber's operational state, wherein the scaling varies as a function of one or more current engine operating parameters; and
summing torques profiles for all of the engine's working chambers to obtain an estimated overall engine torque profile, the summed torque profiles including the torque profile for the selected working chamber.

US Pat. No. 9,891,137

INDUCTION DIAGNOSTICS FOR SKIP FIRE ENGINES

Tula Technology, Inc., S...

1. A method of detecting an induction fault of a cylinder in an internal combustion engine having a crankshaft, the method
comprising:
measuring the angular acceleration of the crankshaft to generate a crankshaft acceleration signal;
comparing the crankshaft angular acceleration signal with a reference angular acceleration wherein the reference is based
at least in part on a commanded skip/fire decision; and

generating a fault signal when an induction fault is detected, wherein the induction fault detection is based at least in
part on a determination that the crankshaft angular acceleration signal has deviated from the reference angular acceleration
by at least a prescribed threshold.

US Pat. No. 9,890,732

VALVE FAULT DETECTION

Tula Technology, Inc., S...

1. A method of identifying valve actuation faults while operating an engine in a skip fire mode, the engine including a plurality
of working chambers and an exhaust system, each working chamber having an associated exhaust valve and being arranged to operate
in a succession of working cycles, each working cycle having a corresponding potential exhaust period the method comprising:
operating the engine in a skip fire mode in which working cycles are selectively skipped or fired;
for each of a multiplicity of selected working cycles estimating an expected exhaust pressure at a selected location in the
exhaust system during a time period corresponding to the associated potential exhaust period;

for each of the multiplicity of selected working cycles measuring an actual exhaust pressure at the selected location in the
exhaust system during the time period corresponding to the associated potential exhaust period; and

for each of the multiplicity of selected working cycles comparing the actual exhaust pressure to the expected exhaust pressure
to determine whether a valve actuation fault has occurred; and

when it is determined that a valve actuation fault has occurred, performing at least one of (a) altering an aspect of control
of the engine while the engine is operating in the skip fire mode in response to said determination; and (b) recording the
detection of the valve actuation fault in a diagnostics system.

US Pat. No. 9,784,644

ENGINE ERROR DETECTION SYSTEM

Tula Technology, Inc., S...

1. A method for detecting misfire in an engine, the engine having a plurality of working chambers and being operated in a
skip fire manner, the method comprising:
assigning a window to a target firing opportunity;
attempting to fire a target working chamber during the target firing opportunity;
measuring a change in an engine parameter during the target firing opportunity;
using a multi-cylinder pressure model to help determine an expected change in the engine parameter during the target firing
opportunity wherein the pressure model involves estimating pressure in a skipped working chamber; and

based on a comparison between the expected change and the measured change, determining whether the target working chamber
misfired.

US Pat. No. 9,664,130

USING CYLINDER FIRING HISTORY FOR COMBUSTION CONTROL IN A SKIP FIRE ENGINE

Tula Technology, Inc., S...

1. An engine controller for an internal combustion engine operated in a skip fire manner, the engine having a plurality of
working chambers, the engine controller comprising:
a firing counter that stores a firing history indicating a number of skips for a working chamber in the engine; and
a combustion control module that is arranged to determine a combustion control parameter used in the control of an actuator
to help manage combustion in the working chamber during the next fired working cycle that occurs in the working chamber, and
wherein the determination of the combustion control parameter is based at least in part on the firing history.

US Pat. No. 9,945,313

MANIFOLD PRESSURE AND AIR CHARGE MODEL

Tula Technology, Inc., S...

1. An engine controller arranged to direct skip fire operation of an internal combustion engine having a plurality of working chambers and an intake manifold, the engine controller comprising:a firing controller arranged to direct operation of the engine in a skip fire mode, the firing controller being arranged to direct a sequence of skip fire firings that delivers a desired engine output while operating at a first effective displacement, wherein during operation of the engine in the skip fire mode at the first effective displacement, a selected one of the working chambers will sometimes be skipped during a first firing opportunity of the selected working chamber and sometime be fired during an immediately following second firing opportunity of the selected working chamber; and
a mass air charge determining unit that is arranged to, for each fired firing opportunity of the plurality of working chambers:
(i) determine a number of firings of all of the working chambers that will have taken place within a designated window corresponding to a fixed number of firing opportunities that immediately preceded such fired firing opportunity;
(ii) determine a firing ratio wherein the firing ratio is a ratio of firings to firing opportunities in the window with the ratio being fractionally less than or equal to 1; and
(iii) estimate a mass air charge based on the firing ratio wherein the mass air charge estimation takes into account fluctuations of intake manifold pressure resulting from skipped firing opportunities; and
cause fuel to be delivered to the working chamber associated with the fired firing opportunity for which the estimated mass air charge was determined based on the estimated mass air charge.

US Pat. No. 9,995,652

INDUCTION DIAGNOSTICS FOR SKIP FIRE ENGINES

Tula Technology, Inc., S...

1. A method of detecting an induction fault in an internal combustion engine having an intake manifold that supplies air to at least one working chamber of the internal combustion engine, and an intake manifold pressure sensor configured to sense an air pressure within the intake manifold, the method comprising:obtaining a first pressure reading indicative of the intake manifold pressure at a time associated with a first working chamber air induction opportunity;
obtaining a second pressure reading indicative of the intake manifold pressure at a time associated with a second working chamber air induction opportunity that follows the first working chamber induction opportunity, the second air induction opportunity being the next air induction opportunity following the first air induction opportunity; and
determining whether an induction fault has occurred in association with the second air induction opportunity based at least in part on the first and second pressure readings.

US Pat. No. 10,012,161

TORQUE ESTIMATION IN A SKIP FIRE ENGINE CONTROL SYSTEM

Tula Technology, Inc., S...

1. A method for performing diagnostics on a skip fire engine control system, the skip fire engine control system including an engine having a plurality of working chambers, the method comprising:calculating an operational engine torque;
operating an engine in a skip fire manner to deliver the operational engine torque;
calculating a reference engine torque using a torque model wherein the torque model involves estimating torque individually for each working chamber;
comparing the reference engine torque to the operational engine torque to assess accuracy of the operational engine torque calculation;
identifying a potential error when a discrepancy between the calculated reference engine torque and the calculated operational engine torque exceeds a threshold; and
performing an action in response to the identification of the potential error.

US Pat. No. 9,689,328

MULTI-LEVEL SKIP FIRE

Tula Technology, Inc., S...

1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers to deliver
a desired output, wherein each working chamber has at least one intake valve that is cam-actuated and at least one exhaust
valve, the method comprising:
operating the engine in a dynamic firing level modulation mode that causes selected low working cycles to be fired at a low
torque output and selected high working cycles to be fired at a high torque output, wherein decisions whether to fire each
working cycle at a high or low torque output are dynamically determined during operation of the engine on a firing opportunity
by firing opportunity basis; and

adjusting an air charge for each fired working cycle based on whether the high or low torque output was selected for such
fired working cycle.

US Pat. No. 9,878,718

COORDINATION OF VEHICLE ACTUATORS DURING FIRING FRACTION TRANSITIONS

Tula Technology, Inc., S...

1. A method of managing firing fraction transitions in a vehicle having a powertrain, the powertrain including an engine and
a drivetrain, the drivetrain including an adjustable slip drivetrain component, the method comprising:
while the engine is operating at a first firing fraction and the adjustable slip drivetrain component is operating at a first
drivetrain slip, determining a requested second firing fraction that is different than the first firing fraction, the second
firing fraction having an associated second drivetrain slip and an associated second drivetrain slip transition threshold
that is higher than the first drivetrain slip;

initiating a transition from the first drivetrain slip towards the second drivetrain slip;
transitioning to a target firing fraction that is different than the first and second firing fractions, the target firing
fraction (i) being selected from a set of available firing fractions capable of delivering a requested engine output, and
(ii) having an associated target drivetrain slip transition threshold that is less than the second drivetrain slip transition
threshold; and

after transitioning to the target firing fraction, transitioning to the second firing fraction, and
wherein each firing fraction transition is constrained to only occur when an actual driveline slip is at least as high as
the associated drivetrain slip transition threshold.

US Pat. No. 9,926,868

COORDINATION OF VEHICLE ACTUATORS DURING FIRING FRACTION TRANSITIONS

Tula Technology, Inc, Sa...

1. A method of controlling an engine to deliver a requested engine output, the method comprising:(a) while the engine is operating at a first firing fraction and an associated first cam phase, determining a requested firing fraction that is different than the first firing fraction, the requested firing fraction being a second firing fraction having an associated second cam phase, the second cam phase being different than the first cam phase;
(b) selecting an intermediate firing fraction that is between the first and second firing fractions, the intermediate firing fraction having an associated intermediate cam phase;
(c) identifying the selected intermediate firing fraction as a target firing fraction and the intermediate cam phase as a target cam phase;
(d) initiating a transition from the first cam phase to one of the second cam phase or the target cam phase;
(e) after an actual cam phase is at or within a predetermined range of the target cam phase transitioning to the target firing fraction;
(f) when the target firing fraction is not the second firing fraction, selecting a next firing fraction having an associated next cam phase and setting the target firing fraction to be the next firing fraction and setting the target cam phase to be the next cam phase and causing the cam phase to transition towards the next cam phase or the second cam phase; and
(g) iteratively repeating (e) and (f) until the requested firing fraction is reached; and
(h) directing operation of the engine during the transitions to deliver the requested engine output, whereby an actual commanded firing fraction changes over a course of the transition.

US Pat. No. 9,982,611

INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY

Tula Technology, Inc., S...

1. A method of controlling the operation of an internal combustion engine having a plurality of working chambers, each working chamber being generally arranged to operate in a succession of working cycles, the method comprising:operating the engine in a skip fire operational mode, wherein during operation of the engine in the skip fire operational mode, a selected one of the working chambers will be fired during some working cycles and not fired during other working cycles; and
adjusting a setting of a component that affects a torque output associated with a selected firing of the selected working chamber based at least in part on a current skip/fire firing history of the selected working chamber.

US Pat. No. 9,835,522

INDUCTION DIAGNOSTICS FOR SKIP FIRE ENGINE

Tula Technology, Inc., S...

1. A method of detecting an induction fault of a cylinder in an internal combustion engine having an intake manifold, the
method comprising:
operating the engine in a skip fire mode using an engine control unit, the engine control unit including a firing timing determining
unit arranged for determining the timing of working chamber firings of the engine when operating in the skip fire mode;

sensing the intake manifold pressure and generating an intake manifold pressure signal indicative of the intake manifold pressure;
filtering the intake manifold pressure signal to reduce low frequency signal components of the intake manifold pressure signal;
comparing the filtered intake manifold pressure signal or a processed version of the filtered intake manifold pressure signal
to a fault threshold; and

generating a fault signal when an induction fault is detected, wherein the induction fault detection is based at least in
part on a determination that the filtered intake manifold pressure signal or the processed version of the filtered intake
manifold pressure signal has passed the fault threshold,

wherein the fault signal is generated when the engine is operating in the skip fire mode.

US Pat. No. 9,739,212

METHOD AND APPARATUS FOR DETERMINING OPTIMUM SKIP FIRE FIRING PROFILE WITH ADJUSTMENTS FOR AMBIENT TEMPERATURE

Tula Technology, Inc., S...

1. A skip fire engine controller comprising:
a skip fire profile module arranged to determine an operational firing fraction and associated cylinder load for delivering
a desired engine output, wherein the operational firing fraction is selected at least in part based on at least one temperature
affecting a coupling of noise and vibration to a vehicle cabin at the selected operational firing fraction; and

a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction.

US Pat. No. 10,138,860

FIRING FRACTION TRANSITION CONTROL

Tula Technology, Inc., S...

1. A method of controlling the transition of an engine between different effective firing fractions, the method comprising:while the engine is operating at a first effective firing fraction using a first value for an operating parameter that affects working chamber air charge, determining a target value for the operating parameter that is different than the first value, and a target effective firing fraction selected to deliver a requested engine output;
transitioning from the first firing effective fraction to the target effective firing fraction;
during the transition, determining a feed forward adjusted effective firing fraction that at least partially compensates for engine dynamics that occur during the change from the initial value for the operating parameter to the target value for the operating parameter, wherein the feed forward adjusted effective firing fraction changes over the course of the transition;
during the transition, determining an effective firing fraction correction factor indicative of a difference between an actual engine output and the requested engine output, wherein the effective firing fraction correction factor potentially varies over the course of the transition;
determining a commanded effective firing fraction during the transition that combines the effective firing fraction correction factor with the feed forward adjusted effective firing fraction; and
directing dynamic firing level modulation operation of the engine utilizing the commanded effective firing fraction during the transition, whereby the commanded effective firing fraction changes over the course of the transition.

US Pat. No. 9,983,583

AUTONOMOUS DRIVING WITH DYNAMIC SKIP FIRE

Tula Technology, Inc., S...

9. A method of controlling the operation of an engine, the method comprising:determining a desired engine torque;
determining a proposed effective operational displacement from a plurality of potentially available effective operational displacements suitable for delivering the desired engine torque, the proposed effective operational displacement being the most fuel efficient effective operational displacement among the plurality of available effective operational displacements;
determining whether there is an alternative effective operational displacement that is capable of delivering an alternative engine torque that is within a designated range of the desired engine torque with better fuel economy than would be provided by operation at the proposed effective operational displacement, the alternative engine torque being different than the desired engine torque; and
when it is determined that an alternative effective operational displacement that is capable of delivering an alternative engine torque that is within the designated range of the desired torque with better fuel economy than the desired engine torque exists, determining whether the alternative engine torque is suitable for use under current operating conditions, and if so, directing operation of the engine at the alternative effective operational displacement to deliver the alternative engine torque, wherein the designated range does not exceed 5% of the desired engine torque such that the alternative effective operational displacement is capable of delivering at least 95% of the desired engine torque.

US Pat. No. 10,088,388

ENGINE ERROR DETECTION SYSTEM

Tula Technology, Inc., S...

1. A method for detecting misfire in an engine, the engine having a plurality of working chambers and being operated in a skip fire manner, the method comprising:assigning a window to a target firing opportunity;
attempting to fire a target working chamber during the target firing opportunity;
measuring a change in an engine parameter during the target firing opportunity;
using a multi-cylinder pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber, wherein the determination of the expected change in the engine parameter accounts for torque added or subtracted from the powertrain by an auxiliary power source;
based on a comparison between the expected change and the measured change, determining whether the target working chamber misfired.

US Pat. No. 9,964,051

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

1. A engine controller suitable for directing operation of an engine in a skip fire manner, the 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 operational firing fraction from a set of available firing fractions; and
a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction, wherein the firing controller includes an accumulator that helps smooth transitions between different firing fractions; and
wherein all of the firing fractions in the set of available firing fractions other than a firing fraction of one, are simple fractions having an integer denominator of no more than 15.

US Pat. No. 10,094,313

COORDINATION OF VEHICLE ACTUATORS DURING FIRING FRACTION TRANSITIONS

Tula Technology, Inc., S...

1. A method of controlling an engine to deliver a requested engine output, the method comprising:(a) while the engine is operating at a first effective firing fraction and an associated first cam phase, determining 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;
(b) selecting 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;
(c) identifying the selected intermediate effective firing fraction as a target effective firing fraction and the intermediate cam phase as a target cam phase;
(d) initiating a transition from the first cam phase to one of the second cam phase or the target cam phase;
(e) after an actual cam phase is at or within a predetermined range of the target cam phase transitioning to the target effective firing fraction;
(f) when the target effective firing fraction is not the second effective firing fraction, selecting a next effective firing fraction having an associated next cam phase and setting the target effective firing fraction to be the next effective firing fraction and setting the target cam phase to be the next cam phase and causing the cam phase to transition towards the next cam phase or to transition towards or to continue transitioning towards the second cam phase; and
(g) iteratively repeating (e) and (f) until the requested effective firing fraction is reached; and
(h) directing 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.

US Pat. No. 10,107,211

SKIP FIRE TRANSITION CONTROL

Tula Technology, Inc., S...

1. An engine controller comprising:a firing fraction determining unit arranged to determine a desired operational firing fraction during operation of the engine; and
a transition adjustment unit arranged to manage transitions from a first firing fraction requested by the firing fraction determining unit to a target firing fraction requested by the firing fraction determining unit that is different from the first firing fraction, the transition adjustment unit being configured to gradually alter a commanded firing fraction from the first firing fraction to the target firing fraction, wherein the commanded firing fraction is altered each firing opportunity.

US Pat. No. 10,167,799

DECELERATION CYLINDER CUT-OFF IN A HYBRID VEHICLE

Tula Technology, Inc., S...

1. A method of operating a vehicle having a drive train, an electric motor/generator and an engine, the engine having a crankshaft, an intake manifold and a plurality of working chamber, and wherein the electric motor/generator and engine cannot independently mechanically engage with the drive train, the method comprising:while the engine is operating with the crankshaft rotating in a first direction, deactivating all the working chambers in response to a no engine torque request such that none of the working chambers are fired and no air is pumped through the working chambers as the crankshaft continues to rotate in the first direction through multiple engine cycles with the working chambers deactivated;
disengaging the engine from the drive train so that the vehicle motion and crankshaft rotation are not mechanically coupled during at least a portion of the time in which all of the working chambers are deactivated, whereby the electric motor/generator is disengaged from the drive train when the engine is disengaged from the drive train; and
allowing the crankshaft rotation rate to drop below a shift speed for multiple engine cycles while the engine is disengaged from the drive train with all of the working chambers deactivated.

US Pat. No. 10,344,692

ADAPTIVE TORQUE MITIGATION BY MICRO-HYBRID SYSTEM

Tula Technology, Inc., S...

1. An electric motor/generator controller for operating a motor/generator used as an auxiliary torque source/sink in a hybrid powertrain, the hybrid powertrain including an internal combustion engine that operates in a firing sequence, the motor/generator controller comprising:a matched basis function control module arranged to generate a control signal for the electric motor/generator, wherein the matched basis function control module is configured to receive a parameter indicative of a firing sequence length, a parameter indicative of a firing sequence phase, a crank angle signal, and a NVH metric signal as inputs and to generate the control signal for the electric motor/generator based at least in part of the received parameter indicative of the firing sequence length, firing sequence phase, the crank angle signal, and the NVH metric signal.

US Pat. No. 10,508,604

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

Tula Technology, Inc., S...

1. A skip fire engine controller comprising:a firing fraction determining unit arranged to determine and output a commanded firing fraction;
a filter arranged to receive the commanded firing fraction and output an operational firing fraction, the filter being arranged to spread changes in the commanded firing fraction over multiple firing opportunities;
a firing controller arranged to direct firings in a skip fire manner that delivers the operational firing fraction; and
a filter bypass that causes the filter to be bypassed such that the commanded firing fraction is passed directly to the firing controller as the operational firing fraction in response to at least one predetermined type of circumstances.

US Pat. No. 10,253,706

AIR CHARGE ESTIMATION FOR USE IN ENGINE CONTROL

Tula Technology, Inc., S...

1. A method comprising:determining that a selected working cycle will be fired during operation of an engine, wherein the firing determination is made before an induction event associated with the selected working cycle begins;
estimating a manifold pressure at a time corresponding to the induction event associated with the selected working cycle, wherein the manifold pressure estimate accounts for impacts from one or more intervening potential induction events that will occur between the time that the manifold pressure is estimated and the time that the induction event associated with the selected working cycle occurs;
utilizing the estimated manifold pressure in the estimation of the air charge for the selected working cycle;
utilizing the estimated air charge in a determination of a desired fuel charge for the selected working cycle; and
causing the desired fuel charge to be injected for the selected working cycle.

US Pat. No. 10,233,796

INTERNAL COMBUSTION ENGINE USING VARIABLE VALVE LIFT AND SKIP FIRE CONTROL

Tula Technology, Inc., S...

1. A method of operating an internal combustion engine having at least one camshaft and a plurality of cylinders, each cylinder having at least one associated cam actuated intake valve, the method comprising:directing skip fire operation of the engine in accordance with a firing fraction that defines a first effective displacement of the engine, wherein during skip fire operation of the engine, for at least one of the cylinders, the cylinder is deactivated during selected skipped cylinder working cycles such that air is not pumped through the cylinder during the skipped cylinder working cycles and selected active cylinder working cycles are fueled and fired, the skipped and active working cycles being interspersed such that the one cylinder is fired, skipped and selectively either fired or skipped during successive work cycles in accordance with the firing fraction, while the engine is operating at the first effective displacement; and
controlling valve lift differently between the cam actuated intake valves associated with at least two of the cylinders such that the valve lift for the cam actuated intake valve associated with a first one of the cylinders is different than the valve lift for the cam actuated intake valve associated with a second one of the cylinders during a selected engine cycle, to thereby independently control an amount of air charge in the respective first and second cylinders during active working cycles that occur in the selected engine cycle; and
wherein at first selected time during operation of the engine, a first set of cylinders are operated in the skip fire manner concurrently with a second set of cylinders being operated using the variable lift control; and
at second selected times during operation of the engine, all of the cylinders in the first cylinder set are deactivated while the cylinders in the second cylinder set are operated using variable lift control.

US Pat. No. 10,436,133

ENGINE TORQUE SMOOTHING

Tula Technology, Inc., S...

4. A method of controlling the transition of an engine between different firing fractions in a hybrid vehicle having an internal combustion engine and an additional power source/sink, the method comprising:while the engine is operating at a first firing fraction, determining a second target firing fraction that is different than the first firing fraction;
determining a firing sequence to transition between the first firing fraction and the second firing fraction;
determining an engine torque profile associated with the firing sequence;
determining a smoothing torque based at least in part of the determined engine torque profile; and
during the transition from the first firing fraction to the second target firing fraction applying the smoothing torque using the additional power source/sink.

US Pat. No. 10,247,121

METHOD AND APPARATUS FOR DETERMINING OPTIMUM SKIP FIRE FIRING PROFILE

Tula Technology, Inc., S...

1. A skip fire engine controller arranged to direct operation of an engine in a skip fire manner to deliver a desired engine output, the skip fire engine controller comprising:a skip fire profile determination unit arranged to determine an operational firing fraction for delivering the desired engine output,
wherein the skip fire profile determination unit is arranged to select the operational firing fraction from among a plurality of candidate firing fractions that are each capable of delivering the desired engine output, each of the plurality of candidate firing fractions having a corresponding maximum allowable cylinder load, wherein each of the corresponding maximum allowable cylinder loads indicates a maximum allowable cylinder torque fraction when the engine is operating at the associated one of the plurality of candidate firing fractions under specified operating conditions,
wherein the maximum allowable cylinder torque fraction for at least some of the plurality of candidate firing fractions at some specified operating conditions is less than one, each of the plurality of candidate firing fractions having an associated maximum allowable engine output that is attainable by operating the engine at such candidate firing fraction at the associated maximum allowable cylinder load,
wherein at a selected engine speed, the maximum allowable engine output for a first one of the candidate firing fractions is higher than the maximum allowable engine output for a second one of the candidate firing fractions, the second one of the candidate firing fractions being higher than the first one of the candidate firing fraction, and
wherein the operational firing fraction is selected at least partially based on the corresponding maximum allowable cylinder load not being exceeded when the engine is firing at the operational firing fraction and operating at the desired engine output; and
a firing control unit arranged to direct firings of cylinders of the engine in the skip fire manner in accordance with the operational firing fraction, the operational firing fraction resulting in the desired engine output of the engine without exceeding the maximum allowable cylinder load associated with the operational firing fraction.

US Pat. No. 10,196,995

ENGINE TORQUE SMOOTHING

Tula Technology, Inc., S...

1. A method of control of a hybrid vehicle having an internal combustion engine and an auxiliary power source/sink, the method comprising:determining a torque profile for the internal combustion engine by;
determining a normalized torque profile for each stroke of a cylinder in the engine, wherein the normalized torque profile is based on intake manifold pressure;
scaling the normalized torque profile to determine the cylinder torque; and
summing the cylinder torques for all cylinders in the engine to obtain an overall engine torque profile;
determining whether the torque profile provides acceptable NVH;
when the torque profile is determined to provide acceptable NVH, operating the hybrid vehicle solely on the output of the internal combustion engine; and
when the torque profile is determined to provide unacceptable NVH, operating the hybrid vehicle on both the internal combustion engine and the auxiliary power source/sink, wherein the auxiliary power source/sink provides a smoothing torque to reduce NVH to an acceptable level.

US Pat. No. 10,161,328

MANAGING SKIP FIRE PHASE TRANSITIONS

Tula Technology, Inc., S...

1. A method of altering the phase of a firing sequence during operation of an engine having a plurality of working chambers at a first firing fraction that is less than one, the method comprising:(a) determining whether a selected working chamber firing decision is consistent with a firing decision that would be made when the firing sequence is in a desired phase; and
(b) when it is determined that the selected working chamber firing decision is not consistent with the firing decision that would be made when the firing sequence is in the desired phase, at least sometimes, adjusting the phase of the firing sequence, wherein adjusting the phase takes place while the engine continues to operate at the first firing fraction; and
(c) repeating steps (a) and (b) as necessary at least until the desired phase is attained, wherein steps (a) and (b) are performed using a first order sigma delta converter during operation of the engine at the first firing fraction; and
whereby the phase of the firing sequence is altered from a first phase to the desired phase, wherein adjusting the phase of the firing sequence while the engine continues to operate at the first firing fraction is accomplished by adding an offset value to an accumulator in the sigma delta converter.

US Pat. No. 10,273,894

INTERNAL COMBUSTION ENGINE CONTROL FOR IMPROVED FUEL EFFICIENCY

Tula Technology, Inc., S...

1. A sigma delta converter arranged to receive an input signal indicative of a desired output and to output a digital output signal reflective of the input signal, the digital output signal being suitable for use in a control of a power plant, the sigma delta converter comprising:an integrator block that includes at least one integrator, wherein the integrator block is arranged to receive one or more inputs that are collectively reflective of the input signal and a feedback signal that is based on the digital output signal;
a comparator that receives an integrated signal from the integrator block and outputs the digital output signal, the digital output signal being reflective of the input signal, wherein a timing of an output of the comparator is based on a clock signal; and
a variable clock that generates the clock signal, wherein the variable clock is configured to receive an indication of a rotational speed of the power plant and vary the clock signal as a function of the rotational speed of the power plant.

US Pat. No. 10,303,169

AUTONOMOUS DRIVING WITH DYNAMIC SKIP FIRE

Tula Technology, Inc., S...

21. An engine control system comprising:an engine controller arranged to direct operation of an engine to deliver a requested torque, wherein the engine controller is capable of directing operation of the engine at a plurality of different effective displacements; and
an autonomous driving unit configured to determine a requested torque, wherein the autonomous driving unit utilizes fuel economy information associated with the different displacements in the determination of the requested torque,
wherein the autonomous driving unit considers the collective fuel economy of a plurality of vehicles in a platoon when determining an operational effective displacement.

US Pat. No. 10,247,072

LEAN BURN INTERNAL COMBUSTION ENGINE EXHAUST GAS TEMPERATURE CONTROL

Tula Technology, Inc., S...

1. An engine controller for operating a lean burn internal combustion engine including a plurality of working chambers with at least one working chamber having a deactivatable intake and/or exhaust valve, the engine controller comprising:a firing fraction selector arranged to select one of more than two firing fractions for operating the engine in a skip fire manner, each of the more than two firing fractions defining different effective engine displacements that are each less than full displacement of the engine;
an aftertreatment monitor arranged to obtain data relating to a temperature of an aftertreatment element in an engine exhaust system; and
a firing timing determination unit that is arranged to determine a firing sequence for operating the at least one working chamber of the engine having a deactivatable intake and/or exhaust valve in the skip fire manner in accordance with the selected firing fraction, wherein the firing sequence is generated at least in part based on the aftertreatment element temperature data; and
wherein the engine controller is configured to selectively direct one or both of the associated intake valve and/or exhaust valve(s) to be deactivated during each skipped working cycle such that air is not pumped through the working chamber into the engine exhaust system,
wherein, for a given effective engine displacement corresponding to the selected firing fraction, the firing sequence for operating the at least one working chamber is determined on a firing opportunity by firing opportunity basis such that a selection of which working cycles to either fire or skip is individually made each firing opportunity in accordance with the selected firing fraction.

US Pat. No. 10,259,461

COORDINATION OF VEHICLE ACTUATORS DURING FIRING FRACTION TRANSITIONS

Tula Technology, Inc., S...

1. A method of managing firing fraction transitions in a vehicle having a powertrain that includes an engine and a drivetrain that includes an adjustable slip drivetrain component, the method comprising:while the engine is operating at a first firing fraction and the adjustable slip drivetrain component is operating at a first drivetrain slip, determining a requested second firing fraction that is different than the first firing fraction, the second firing fraction having an associated second drivetrain slip and an associated second drivetrain slip transition threshold that is higher than the first drivetrain slip;
initiating a transition from the first drivetrain slip towards the second drivetrain slip;
transitioning to a target firing fraction that is different than the first and second firing fractions, the target firing fraction (i) being selected from a set of available firing fractions capable of delivering a requested engine output, and (ii) having an associated target drivetrain slip transition threshold that is less the second drivetrain slip transition threshold; and
after transitioning to the target firing fraction, transitioning to the second firing fraction, and
wherein each firing fraction transition is constrained to only occur when an actual driveline slip is at least as high as the associated drivetrain slip transition threshold.

US Pat. No. 10,494,971

LEAN BURN INTERNAL COMBUSTION ENGINE EXHAUST GAS TEMPERATURE CONTROL

Tula Technology, Inc., S...

1. A method of reducing accumulated soot in a particulate filter utilized in an exhaust path of a lean burn internal combustion engine having a plurality of working chambers, each working chamber being configured to operate in a series of successive working cycles, the method comprising:during operation of the lean burn internal combustion engine, transitioning to a particulate filter cleaning mode, in which the lean burn internal combustion engine is operated in a skip fire mode to increase the temperature of exhaust gases sufficiently to raise the temperature of the particulate filter sufficiently to oxidize and thereby remove soot accumulated on the particulate filter; and
operating the lean burn internal combustion engine in the skip fire mode by:
(a) operating the lean burn internal combustion engine at a reduced effective displacement that is less than the full displacement of the lean burn internal combustion engine;
(b) for a select effective reduced displacement, directing at least one of the plurality of working chambers over a number of working cycles to be (i) fired causing a combustion event in some working cycles and (ii) skipped resulting in no combustion event in other working cycles; and
(c) at the select effective reduced displacement, preventing air from pumping through the at least one working chamber during one or more of the skipped working cycles.

US Pat. No. 10,221,786

NOISE, VIBRATION AND HARSHNESS REDUCTION IN A SKIP FIRE ENGINE CONTROL SYSTEM

Tula Technology, Inc., S...

1. A powertrain controller for directing operation of an internal combustion engine having a plurality of cylinders, each cylinder being arranged to operate in a sequence of working cycles, each working cycle having an associated firing opportunity, the internal combustion engine having an associated engine cycle that constitutes one firing opportunity for each cylinder, the powertrain controller comprising:a firing controller arranged to direct firings in a sequence of cylinder working cycles, wherein selected first working cycles are directed to have a greater torque output than selected second working cycles within the same engine cycle, the first and second working cycles being interspersed; and
an NVH reduction module that is configured to (a) determine a smoothing torque to be applied to a powertrain by an energy storage/release device, the determination of the smoothing torque being affirmatively made during operation of the engine, and (b) direct the energy storage/release device to apply the smoothing torque to the powertrain, wherein the smoothing torque is arranged to at least partially cancel out a variation in torque output generated by the first and second working cycles, and (c) select a magnitude of the smoothing torque based on fuel efficiency and further based on whether the smoothing torque brings NVH generated by the operation of the engine below a predefined NVH target level.

US Pat. No. 10,493,836

NOISE/VIBRATION CONTROL USING VARIABLE SPRING ABSORBER

Tula Technology, Inc., S...

10. A system for reducing at least one of noise and vibration generated by an internal combustion engine during operation of the engine, the system comprising:a powertrain that includes the engine and a variable spring absorber;
an engine controller configured to direct operation of the engine in a cylinder output level modulation mode; and
an absorber controller arranged to set an absorption frequency for the variable spring absorber during cylinder output level modulation operation of the engine, wherein the absorption frequency is set based at least in part on a minimum repeating pattern length of a repeating firing sequence associated with an operational firing fraction and level fraction.

US Pat. No. 10,393,085

MANAGING FIRING PHASE TRANSITIONS

Tula Technology, Inc., S...

1. An engine controller configured to direct operation of an engine having a plurality of working chambers at a first effective firing fraction that is less than one, the engine controller being configured to:(a) determine whether a selected working chamber firing decision is consistent with a firing decision that would be made when a firing sequence associated with the first effective firing fraction is in a desired phase; and
(b) when it is determined that the selected working chamber firing decision is not consistent with the firing decision that would be made when the firing sequence is in the desired phase, at least sometimes, adjusting the phase of the firing sequence; and
(c) repeating steps (a) and (b) as necessary at least until the desired phase is attained, wherein steps (a) and (b) are performed by a first order sigma delta converter during operation of the engine at the first effective firing fraction; and
whereby the phase of the firing sequence is altered from a first phase to the desired phase while the engine continues to operate at the first effective firing fraction by adding an offset value to an accumulator in the sigma delta converter.

US Pat. No. 10,519,876

CONTROLLER SYSTEM AND METHOD FOR SELECTING A FIRING FRACTION FOR A SKIP FIRE CONTROLLED INTERNAL COMBUSTION ENGINE BASED AT LEAST ON NON-DRIVE TRAIN LEVELS OF NOISE, VIBRATION AND HARSHNESS

Tula Technology, Inc., S...

1. A skip fire engine controller, comprising:a skip fire profile module arranged to monitor noise and vibration generated by one or more sources external to an engine and determine an operational firing fraction and associated cylinder load for delivering a desired engine output, wherein the selection of the operational firing fraction is based at least in part on whether the noise and vibration generated external to the engine at least partially masks noise and vibration generated by the engine; and
a firing controller arranged to direct firings of one or more cylinders of the engine in a skip fire manner that delivers the selected operational firing fraction,
wherein the engine when operating at the selected operational firing fraction has at least one cylinder that is fired, skipped and either fired or skipped over successive firing opportunities.

US Pat. No. 10,557,427

MULTI-LEVEL FIRING ENGINE CONTROL

Tula Technology, Inc., S...

1. A method of controlling operation of an internal combustion engine having a plurality of working chambers to deliver a desired output, wherein each working chamber has at least one cam-actuated intake valve and at least one exhaust valve, the plurality of working chambers including first and second sets of the working chambers, each set of working chambers including at least one working chamber, wherein working chambers in the first set are deactivatable and working chambers in the second set are not capable of being deactivated during operation of the engine, the method comprising:operating the engine to deliver a desired engine output by causing each of the working chambers in the second set to be fired during every engine cycle and causing the working chambers in the first set to sometimes be fired and sometimes be skipped; and
setting an air charge for each fired working cycle based on whether a high or low torque output was selected for the fired working cycle, whereby within a selected engine cycle, at least one fired working chamber has the high torque output and at least one other fired working chamber has the low torque output.

US Pat. No. 10,518,764

SYSTEM AND METHOD FOR IMPROVING FUEL ECONOMY FOR AUTONOMOUS DRIVING VEHICLES

Tula Technology, Inc., S...

1. A vehicle capable of autonomous operation, comprising:an engine having a plurality of working chambers;
an autonomous driving unit arranged to coordinate autonomous driving of the vehicle, including defining a requested torque demand for the engine; and
a controller, responsive to the autonomous driving unit, for controlling the operation of the engine to deliver the requested torque demand by either:
operating the engine at a first firing fraction that defines a first effective displacement of the engine when an occupant is present in the vehicle; or
operating the engine at a second firing fraction that defines a second effective displacement of the engine when an occupant is not present in the vehicle,
wherein the second effective displacement is more fuel efficient than the first engine displacement,
wherein the controller is further arranged to operate the engine at the first effective displacement by operating the working chambers of the engine at the first effective firing fraction and operate the engine at the second effective displacement by operating the working chambers of the engine at the second effective firing fraction.

US Pat. No. 10,408,140

ENGINE CONTROL IN FUEL AND/OR CYLINDER CUT OFF MODES BASED ON INTAKE MANIFOLD PRESSURE

Tula Technology, Inc., S...

1. A controller configured to control operation of an engine in a vehicle, the controller configured to:deactivate all working chambers of the engine in a cylinder cut off mode such that none of the working chambers are fired and no air is pumped through the working chambers from an air intake manifold to an exhaust system of the vehicle;
determining when the operation of the engine is to transition from the cylinder cut off mode to a second operational mode in response to an input to the controller;
measure intake manifold absolute pressure (MAP) in the air intake manifold; and
if the measured MAP is larger than a threshold MAP:
determine, based on the measured MAP, a number of working cycle(s) needed to pump down the measured MAP to below the threshold MAP;
operate the engine so as to pump air from the air intake manifold to the exhaust system through one or more of the working chambers of the engine for the determined number of working cycle(s); and
operate the engine in the second operational mode after the pumping of the air for the determined number of working cycle(s).

US Pat. No. 10,400,691

NOISE/VIBRATION REDUCTION CONTROL

Tula Technology, Inc., S...

1. A method of mitigating or adjusting an NVH characteristic of a vehicle having a powertrain having an engine during cylinder output level modulation operation of the engine, the engine including a plurality of working chambers, the method comprising:operating the engine in a cylinder output level modulation mode at a first effective firing fraction, wherein operation of the engine at the first effective firing fraction causes the working chambers to be fired in a repeating firing sequence having a defined repeating minimum cycle length that is not an integer factor or multiple of the number of working chambers in the engine; and
actively controlling a device that is not a part of the powertrain in a feed forward manner during the cylinder output level modulation operation at the first effective firing fraction based at least in part on a current engine speed and at least one of the minimum repeating pattern length, the first effective firing fraction or a then current operational engine order, to alter the NVH characteristic of the vehicle in a desired manner.

US Pat. No. 10,635,105

AUTONOMOUS DRIVING WITH DYNAMIC SKIP FIRE

Tula Technology, Inc., S...

18. A vehicle, comprising:an engine controller arranged to: direct operation of an engine of a vehicle operating in a platoon to selectively operate at one of a plurality of different effective displacements; and
an autonomous driving unit configured to determine a requested torque demand based at least partially on sensed operational conditions of the vehicle as provided to the autonomous driving unit, wherein the autonomous driving unit utilizes fuel economy information associated with the different effective displacements of the engine to determine a modified torque demand,
wherein the engine controller and the autonomous driving unit cooperate to operate the engine to meet the modified torque request, which is more fuel efficient compared to operating the vehicle at the requested torque demand based at least partially on the sensed operational conditions,
wherein the autonomous driving unit considers the collective fuel economy of multiple vehicles operating in the platoon when determining an operational effective displacement.

US Pat. No. 10,634,076

NOISE/VIBRATION REDUCTION CONTROL

Tula Technology, Inc., S...

1. A method of mitigating or adjusting an NVH characteristic of a vehicle having a powertrain that includes an engine capable of skip fire operation, the engine including a plurality of working chambers, the method comprising:operating the engine in a skip fire mode at a first effective displacement; and
actively controlling a device that is not a part of the powertrain in a feed forward manner, during the skip fire operation at the first effective displacement, to alter the NVH characteristic of the vehicle in a desired manner based at least in part on specific individual skip fire firing decisions, each specific individual skip fire firing decision being indicative of whether to skip or fire an individual working chamber during a single associated skip fire firing opportunity, wherein for each skip fire firing decision, the device is controlled differently during the associated skip fire firing opportunity based on whether the associated skip fire firing decision is a skip or a fire, the control of the device varying over the course of each engine cycle in accordance with the specific individual skip fire firing decisions associated with that engine cycle during the skip fire operation of the engine at the first effective displacement.

US Pat. No. 10,578,037

ADAPTIVE TORQUE MITIGATION BY MICRO-HYBRID SYSTEM

Tula Technology, Inc., S...

1. A powertrain controller for operating an internal combustion engine in a dynamic firing level modulation manner using an operational effective firing fraction that is fuel efficient and has acceptable noise, vibration and harshness (NVH) characteristics, the powertrain controller comprising:a firing fraction calculator arranged to generate an operational effective firing fraction to deliver a requested engine torque; and
a firing determination timing module that is arranged to generate a firing sequence used to operate the engine in a dynamic firing level modulation manner, the firing sequence being based on the operational effective firing fraction;
wherein the powertrain controller uses an adaptive filter feed forward controller that is arranged to determine a smoothing torque that is applied to a powertrain by an energy storage/capture/release device,
wherein the smoothing torque is arranged to at least partially cancel out a variation in torque generated by the firing sequence, thereby reducing NVH that would otherwise be generated by the firing sequence.

US Pat. No. 10,619,584

DYNAMIC VALVE CONTROL IN A SKIP FIRE CONTROLLED ENGINE

Tula Technology, Inc., S...

37. A computer readable storage medium that includes executable computer code embodied in a tangible form and suitable for operating an internal combustion engine in a skip fire manner that is fuel efficient and has acceptable noise, vibration and harshness (NVH) characteristics, wherein the computer readable medium includes:executable computer code for generating a fire/skip sequence to deliver a desired torque, wherein the fire/skip sequence includes a type of gas spring associated with each skipped firing opportunity.

US Pat. No. 10,662,883

INTERNAL COMBUSTION ENGINE AIR CHARGE CONTROL

Tula Technology, Inc., S...

1. A method of operating an internal combustion engine having a plurality of cylinders, each cylinder having at least one associated intake valve and an associated exhaust valve, the intake and exhaust valves being cam actuated, the method comprising:directing skip fire operation of the engine, wherein during the skip fire operation of the engine, at least one of the cylinders (i) is deactivated during selected skipped cylinder working cycles such that air is not pumped through the cylinder during the skipped cylinder working cycles, and (ii) selected active cylinder working cycles are fueled and fired, and (iii) the skipped and active working cycles are interspersed while the engine is operating at a first effective displacement; and
controlling the intake valves associated with at least two of the fired cylinder working cycles differently such that a first air charge associated with a first one of the cylinder working cycles is greater than a second air charge associated with a second one of the cylinder working cycles during a selected engine cycle in which neither the first or second cylinder working cycles are skipped, whereby the skipped working cycles, cylinder working cycles having the first air charge and cylinder working cycles having the second air charge are all interspersed while the engine is operating at the first effective displacement.

US Pat. No. 10,611,359

MANAGING ENGINE FIRING FRACTION CHANGES DURING GEAR SHIFTS

Tula Technology, Inc., S...

1. A method of managing a powertrain having an internal combustion engine and a transmission during transmission gear changes, the method comprising:receiving an indication of a proposed gear change indicative of an intent to shift from a first transmission gear to a second transmission gear, the first transmission gear being a current operational gear;
in response to the indication of the proposed gear change, determining whether a first effective firing fraction that is a current operational effective firing fraction is suitable for use in association with the second transmission gear after the proposed gear change is completed;
when it is determined that the current effective firing fraction is not suitable for use after the gear change is completed, directing a change to a second effective firing fraction that is suitable for use in association with the second transmission gear after the proposed gear change is completed, the second effective firing fraction being different than the first effective firing fraction; and
shifting from the first transmission gear to the second transmission gear, wherein the change to the second effective firing fraction occurs before the shift to the second transmission gear is completed.

US Pat. No. 10,830,166

NOISE, VIBRATION AND HARSHNESS REDUCTION IN A SKIP FIRE ENGINE CONTROL SYSTEM

Tula Technology, Inc., S...

1. A method for operating a hybrid powertrain having an internal combustion engine and an energy storage/release device, wherein both the internal combustion engine and the energy storage/release device can deliver torque to the hybrid powertrain, the method comprising:determining an output torque request for the hybrid powertrain;
controlling the internal combustion engine and energy storage/release device so as to meet the torque request; and
using the energy storage/release device to provide a smoothing torque to at least partially cancel hybrid powertrain torque oscillations generated by the internal combustion engine;
wherein a DC term is added to the smoothing torque, wherein energy costs are considered in determining the smoothing torque,
wherein the DC term can have either sign such that the energy storage/release device can store energy from the hybrid powertrain or release energy to the hybrid Powertrain.

US Pat. No. 10,814,858

MANAGING ENGINE FIRING FRACTION CHANGES DURING GEAR SHIFTS

Tula Technology, Inc., S...

1. A method of managing a powertrain having an internal combustion engine and a transmission during power-on up-shift transmission gear changes, the internal combustion engine being configured to operate in a skip fire operating mode, the method comprising:receiving an indication of a proposed gear change indicative of an intent to up-shift from a first transmission gear to a second transmission gear while the engine is operating at a first firing fraction that is less than one, the first transmission gear being a current operational gear and the second transmission gear being higher than the first transmission gear;
transitioning from the first firing fraction to a firing fraction of one after receiving the indication of the proposed gear change;
implementing a power-on up-shift in response to the indication of the proposed gear change, the power-on up-shift including a torque phase and an inertia phase that follows the torque phase, wherein the transition to the firing fraction of one is completed before entering the inertia phase of the power-on up-shift; and
after completing the power-on up-shift, transitioning from the firing fraction of one to a second firing fraction suitable for use in the second transmission gear, the second firing fraction being a skip fire firing fraction.

US Pat. No. 10,982,617

SPLIT DIRECT INJECTION FOR REACTIVATED CYLINDERS OF AN INTERNAL COMBUSTION ENGINE

Tula Technology, Inc., S...

1. A vehicle, comprising:an internal combustion engine having a cylinder;
a direct fuel injector; and
an engine controller configured to:
(a) deactivate the cylinder and operating the cylinder as a Low Pressure Exhaust Spring (LPES) during a first working cycle;
(b) activate the cylinder during a second working cycle that follows the first working cycle; and
(c) direct the direct fuel injector to directly inject two or more pulses of fuel into the cylinder during the second working cycle, the engine controller making a decision to direct the fuel injector to directly inject the two or more pulses of fuel during the second working cycle at least partially based on a cooling profile of the cylinder while operated as the LPES type gas spring, wherein the direct injection of the two or more pulses reducing particulate emissions compared to the direct injection of a single pulse of fuel.

US Pat. No. 10,968,841

FIRING FRACTION MANAGEMENT IN SKIP FIRE ENGINE CONTROL

TULA TECHNOLOGY, INC., S...

1. An engine controller suitable for directing operation of an engine having a plurality of working chambers in a skip fire manner, the engine controller comprising:a firing fraction determining unit arranged to select an operational firing fraction from a set of available firing fractions; and
a first order sigma delta converter based firing controller arranged to direct working cycle firings in a skip fire manner that delivers the selected operational firing fraction.

US Pat. No. 10,954,877

ADAPTIVE TORQUE MITIGATION BY MICRO-HYBRID SYSTEM

Tula Technology, Inc., S...

1. An electric motor/generator controller for operating a motor/generator used as an auxiliary torque source/sink in a hybrid powertrain, the hybrid powertrain including an internal combustion engine that operates in a firing sequence, the motor/generator controller comprising:a matched basis function control module arranged to generate a control signal for the electric motor/generator; and
a secondary path dynamics module arranged to determine a dynamic response of a secondary path, the secondary path being the response of the motor/generator to a motor/generator control signal, wherein the control signal of the matched basis function control module is affected by the determined dynamic response of the secondary path.

US Pat. No. 10,941,722

METHOD AND APPARATUS FOR DETERMINING OPTIMUM SKIP FIRE FIRING PROFILE

Tula Technology, Inc., S...

1. A skip fire engine controller arranged to direct operation of an internal combustion engine in a skip fire manner to deliver a desired engine output, the skip fire engine controller comprising a firing fraction determining unit arranged to determine an operational firing fraction for delivering the desired engine output under selected operating conditions and a firing control unit arranged to direct firings of cylinders of the internal combustion engine in the skip fire manner in accordance with the operational firing fraction, wherein the firing fraction determination unit is arranged to:identify a plurality of candidate firing fractions that are each capable of delivering the desired engine output under the selected operating conditions, each of the plurality of candidate firing fractions having a corresponding maximum allowable cylinder load associated with the selected operating conditions, wherein at specified operating conditions, the maximum allowable cylinder load for a first one of the candidate firing fractions is higher than the maximum allowable cylinder load for a second one of the candidate firing fractions, the second one of the candidate firing fractions being higher than the first one of the candidate firing fractions;
for at least one of the candidate firing fractions, determine a corresponding expected cylinder load that would be required to operate the internal combustion engine at such candidate firing fraction;
for at least one of the candidate firing fractions, determine whether the expected cylinder load for the candidate firing fraction exceeds the corresponding maximum allowable cylinder load for such candidate firing fractions; and
selecting an operational firing fraction from the plurality of candidate firing fractions, the selected operational firing fraction being constrained such that the corresponding expected cylinder load is no greater than the maximum allowable cylinder load for the selected operational firing fraction.

US Pat. No. 10,927,780

ADAPTATION OF SKIP FIRE CALIBRATION TO VEHICLE WEIGHT

Tula Technology, Inc., S...

1. A platform powered by a skip fire controlled internal combustion engine having a plurality of working chambers that provide motive power capable of moving the platform comprising:a sensor or model that outputs a signal indicative of a weight of the platform; and
an engine controller that determines a skip fire profile which includes an operational firing fraction and a working chamber load, wherein engine operation at the skip fire profile produces an acceptable level of noise, vibration, and harshness and results in combustion conditions in fired working chambers closer to an optimal combustion condition as compared to any other possible skip fire profile, wherein the skip firing profile is adjusted based at least in part on the signal indicative of the platform weight.

US Pat. No. 11,060,430

LEAN BURN INTERNAL COMBUSTION ENGINE EXHAUST GAS TEMPERATURE CONTROL

Tula Technology, Inc., S...


1. A method of operating a lean burn internal combustion engine having one or more working chambers, the method comprising:selectively firing or skipping one or more working cycles of the one or more working chambers, wherein one of the one or more working chambers may be fired during one engine cycle and then skipped during the next engine cycle and selectively skipped or fired during the next engine cycle; and
injecting fuel during at least some of the skipped working cycles such that at least some of the injected fuel is introduced into an exhaust stream fluidly coupled to the one or more working chambers;
wherein injecting fuel comprises initiating injection of the fuel at a location in a power stroke of the skipped working cycle so that little or no combustion occurs resulting in uncombusted fuel in the exhaust stream.

US Pat. No. 11,053,828

SEPARATELY DETERMINING FIRING DENSITY AND PUMPING DENSITY DURING FIRING DENSITY TRANSITIONS FOR A LEAN-BURN INTERNAL COMBUSTION ENGINE

Tula Technology, Inc., S...


1. An engine controller in a vehicle for controlling a lean burn internal combustion engine having a plurality of working chambers, each working chamber being configured to operate in a series of working cycles each having an associated firing opportunity, the controller configured to:direct operation of the internal combustion engine at a first firing density suitable to meet a first torque demand for the internal combustion engine;
determine a target firing density suitable to meet a requested torque demand for the internal combustion engine;
determine an intermediate firing density associated with a transition from the first firing density to the target firing density;
determine a pumping density associated with the transition from the first firing density to the target firing density;
direct operation of the internal combustion engine during the transition by:
selectively firing or not firing each working chamber firing opportunity in accordance with the determined intermediate firing density;
for each working cycle which is not fired, selectively either (a) pumping or (b) not pumping air through the associated working chamber in accordance with the determined pumping density, whereby some of the working cycles that are not fired pump air through the associated working chamber and others of the working cycles that are not fired do not pump air through the associated working chamber during the transition from the first firing density to the target firing density.

US Pat. No. 11,008,995

DYNAMIC CHARGE COMPRESSION IGNITION ENGINE WITH MULTIPLE AFTERTREATMENT SYSTEMS

Tula Technology, Inc., S...

1. A method of controlling operation of an internal combustion engine having a plurality of working chambers, the method comprising:operating the internal combustion engine in a skip fire operational mode wherein one or more working cycles of the plurality of working chambers are either selectively fired or skipped;
during some fired working cycles, using a lean air-fuel mixture and selectively operating the associated working chambers in one of a Homogeneous Charge Compression Ignition (HCCI) mode, a Gasoline Direct Compression Ignition (GDCI) mode, a Spark Assisted Compression Ignition Mode (SACI) mode, or a Dynamic Charge Compression Ignition (DCCI) mode; and
during other fired working cycles, selectively firing the associated working chambers using a stoichiometric air-fuel mixture, and
wherein the lean air-fuel mixture firings and the stoichiometric firings are intermixed.

US Pat. No. 10,900,425

ENGINE DIAGNOSTICS DURING CYLINDER CUT OFF OPERATION

Tula Technology, Inc., S...

1. A method of conducting a diagnosis during deceleration cylinder cutoff (DCCO) operation of an engine having an associated exhaust system and an associated sensor capable of monitoring an amount of oxygen in the exhaust system, the method comprising:operating the engine in the DCCO mode;
monitoring changes in the amount of oxygen in the exhaust system while operating the engine in the DCCO mode;
determining whether the changes in the amount of oxygen in the exhaust system is potentially indicative of a cylinder deactivation fault; and
indicating a potential cylinder deactivation fault when it is determined that the change of the amount of oxygen in the exhaust system is potentially indicative of a cylinder deactivation fault.

US Pat. No. 10,837,382

MULTI-LEVEL FIRING ENGINE CONTROL

Tula Technology, Inc., S...

1. A method of controlling operation of an internal combustion engine with an intake manifold and a plurality of working chambers to deliver a requested torque output, wherein each working chamber has at least one cam-actuated intake valve and at least one exhaust valve, the method comprising:requesting no torque output from the internal combustion engine;
shutting the intake and exhaust valves of all of the plurality of working chambers so that no air is delivered from the intake manifold into the working chambers of the internal combustion engine;
requesting a torque output from the internal combustion engine; and
in response to the torque output request, firing a selected working chamber of the plurality of working chambers during a selected working cycle, wherein the selected working chamber is capable of being fired at a high torque output level and a low torque output level, and the low torque output level is used unless the requested torque output exceeds a predetermined threshold, wherein an air charge is adjusted to obtain the low torque output level.

US Pat. No. 10,823,029

DETERMINING FIRING DENSITY OF A SKIP FIRE CONTROLLED LEAN-BURN ENGINE USING AIR-FUEL RATIO AND EXHAUST TEMPERATURES

Tula Technology, Inc., S...

1. An internal combustion engine having a plurality of cylinders, each of the cylinders arranged to combust an air-fuel mixture characterized by an air-fuel ratio, comprising:a skip fire controller arranged to operate the internal combustion engine in a skip fire mode by ascertaining a firing density to selectively operate the internal combustion engine at a reduced effective displacement, which is less than a full displacement of the internal combustion engine,
the skip fire controller determining the firing density using a combination of:
(a) a temperature of exhaust gases exhausted from the internal combustion engine;
(b) the air-fuel ratio of the air-fuel mixture contained in one or more of the cylinders; and
(c) a torque request,
wherein, when operating at the ascertained firing density, at least one cylinder of the internal combustion engine is fired, skipped, and either selectively fired or skipped over successive firing opportunities; and
a boost controller arranged to at least partially define an intake pressure for the plurality of cylinders, the boost controller arranged to define the intake pressure based at least partially on the firing density ascertained by the skip fire controller.

US Pat. No. 10,816,438

MACHINE LEARNING FOR MISFIRE DETECTION IN A DYNAMIC FIRING LEVEL MODULATION CONTROLLED ENGINE OF A VEHICLE

Tula Technology, Inc., S...

1. A vehicle with an internal combustion engine and a crankshaft for translating motion of pistons of the internal combustion engine into rotation, comprising:a firing level modulation module arranged to operate the internal combustion engine at a reduced effective displacement that is less than full displacement of the internal combustion engine by selectively modulating torque outputs of a cylinder, the modulated torque outputs including either or both of:
(a) no torque output by intentionally skipping and not firing the cylinder; and
(b) one or more torque output level(s) generated by controlling firing of the cylinder; and
a machine learning module arranged to detect a misfire of the cylinder by learning to differentiate between an actual misfire of the cylinder versus either or both of:
(c) the no torque output resulting from the intentional skipping and not firing of the cylinder; and
(d) the one or more torque output level(s) resulting from controlling the firing of the cylinder.

US Pat. No. 10,808,672

DYNAMIC CHARGE COMPRESSION IGNITION ENGINE WITH MULTIPLE AFTERTREATMENT SYSTEMS

Tula Technology, Inc., S...

1. A method of controlling the operation of a variable displacement internal combustion engine having a plurality of working chambers arranged to selectively operate at a reduced effective displacement that is less than full displacement of the internal combustion engine, the method comprising:operating the engine in a firing level modulation mode when operating at the reduced effective displacement, the operation of the engine in the firing level modulation mode involving controlling first working cycles to be fired and to generate a low torque output and controlling second working cycles to be fired and to generate a high torque output, wherein the low torque outputs of the first working cycles are interspersed with the high torque outputs of the second working cycles; and
using different types of working cycles as the first working cycles are fired at the low torque output and the second working cycles are fired at the high torque output, wherein the different types of working cycles include a low temperature gasoline combustion working cycle.

US Pat. No. 10,787,979

ENGINE TORQUE SMOOTHING

Tula Technology, Inc., S...

1. A method of operating a vehicle having an internal combustion engine and an additional power source/sink, the engine having working chambers capable of activation and deactivation and the outputs of the engine and additional power source/sink being combined in a powertrain, the method comprising, during operation of the engine:deactivating, in a cylinder deactivation mode, all of the working chambers in response to a no engine torque request such that none of the working chambers are fired and no air is pumped through the working chambers as the crankshaft rotates;
receiving a torque request;
determining an engine torque profile based on the torque request; and
determining a smoothing torque to be applied by the additional power source/sink that is combined with the engine torque in the vehicle powertrain to deliver the requested torque and maintain acceptable NVH performance during activation of at least one of the engine working chambers, the smoothing torque determined at least partially to compensate for a torque surge caused by an increase in Manifold Absolute Pressure (MAP) during the cylinder deactivation mode; and
applying the smoothing torque in conjunction with the activation of the at least one of the engine working chambers as the internal combustion engine exits the cylinder deactivation mode.