Abstract: Engine controllers and control schemes that facilitate skip fire engine operation in conjunction with use power take-off devices are described. In one aspect, a skip fire mode is exited when the power take-off unit is engaged and the current torque request exceeds a torque threshold. In some embodiments, the exit is delayed when the temperature of an after treatment system is below a designated temperature threshold. In another aspect, the engine transitions to the skip fire mode when the power take-off unit disengages. In some embodiments, exiting is conditioned on the current torque request being less than a torque threshold. In some embodiments, the transition is made immediately, whereas in others the transition only occurs when the power take-off unit is not reengaged for a period of time or is further conditioned on determining that the power take-off unit is likely to remain disengaged for the period of time.

Abstract: An internal combustion engine operates so that it delivers zero or negative torque. The engine operates in either a deceleration cylinder cut off (DCCO) mode or skip cylinder compression braking mode. In the skip cylinder compression braking mode, selected working cycles of selected working chambers are operated in a compression release braking mode. Accordingly, individual working chambers are sometimes not fired and sometimes operated in the compression release braking mode while the engine is operating in the skip cylinder compression braking mode.

Abstract: Controllers and methods for managing transitions into and/or out of a cylinder cut off mode are described. In some embodiments, a skip fire based transition into a cylinder cut off mode is used in which the fraction of working cycles that are fired is gradually reduced to a threshold firing fraction. Once the threshold firing fraction has been reached, all of the working chambers are deactivated.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: Various methods and arrangements for improving fuel economy and noise, vibration, and harshness (NVH) in a skip fire controlled engine are described. An engine controller dynamically selects a gas spring type for a skipped firing opportunity. Determination of the skip/fire pattern and gas spring type may be made on a firing opportunity by firing opportunity basis.

Abstract: Engine controllers and control schemes that facilitate skip fire engine operation in conjunction with use power take-off devices are described. In one aspect, a skip fire mode is exited when the power take-off unit is engaged and the current torque request exceeds a torque threshold. In some embodiments, the exit is delayed when the temperature of an after treatment system is below a designated temperature threshold. In another aspect, the engine transitions to the skip fire mode when the power take-off unit disengages. In some embodiments, exiting is conditioned on the current torque request being less than a torque threshold. In some embodiments, the transition is made immediately, whereas in others the transition only occurs when the power take-off unit is not reengaged for a period of time or is further conditioned on determining that the power take-off unit is likely to remain disengaged for the period of time.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: Various methods and arrangements for improving fuel economy and noise, vibration, and harshness (NVH) in a skip fire controlled engine are described. An engine controller dynamically selects a gas spring type for a skipped firing opportunity. Determination of the skip/fire pattern and gas spring type may be made on a firing opportunity by firing opportunity basis.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: Controllers and methods for managing transitions into and/or out of a cylinder cut off mode are described. In some embodiments, a skip fire based transition into a cylinder cut off mode is used in which the fraction of working cycles that are fired is gradually reduced to a threshold firing fraction. Once the threshold firing fraction has been reached, all of the working chambers are deactivated.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: An internal combustion engine operates so that it delivers zero or negative torque. The engine operates in either a deceleration cylinder cut off (DCCO) mode or skip cylinder compression braking mode. In the skip cylinder compression braking mode, selected working cycles of selected working chambers are operated in a compression release braking mode. Accordingly, individual working chambers are sometimes not fired and sometimes operated in the compression release braking mode while the engine is operating in the skip cylinder compression braking mode.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: A variety of methods and arrangements are described for controlling transitions between firing fractions during skip fire or dynamic firing level modulation operation of an engine. In general, actuator first transition strategies are described in which an actuator position (e.g., cam phase, TCC slip, etc.) is changed to, or close to a target position before a corresponding firing fraction change is implemented. When the actuator change associated with a desired firing fraction change is relatively large, the firing fraction change is divided into a series of two or more firing fraction change steps. A number of intermediate target selection schemes are described as well.

Abstract: In one aspect, a skip fire engine controller is described. The skip fire engine controller includes a skip fire module arranged to determine an operational firing fraction and associated cylinder load for delivering a desired engine output. The skip fire engine controller also includes a firing controller arranged to direct firings in a skip fire manner that delivers the selected operational firing fraction. Various methods, modules, lookup tables and arrangements related to the selection of a suitable operational firing fraction are also described.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

Abstract: Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.