Tula Technology, Inc.

Systems and methods for mitigating exhaust gas emissions via cylinder deactivation are provided. A system includes a controller coupled to an internal combustion engine and an electric motive device. The controller includes a processor and a memory. The memory stores instruction that, when executed by the processor, cause the controller to: receive a power request less than a current power output from the internal combustion engine; command the electric motive device to provide a supplemental power output based on the received power request; command the internal combustion engine to operate in a cylinder deactivation mode whereby at least one cylinder of a plurality of cylinders of the internal combustion engine is deactivated; responsive to determining that a power output of the internal combustion engine is substantially equivalent to the power request after commanding the internal combustion engine to operate in the cylinder deactivation mode, deactivate the electric motive device.

A variety of methods and arrangements for mitigating powertrain and accessory torsional oscillation through electric motor/generator control are described. In one aspect, working chamber air charge and crank position are determined prior to starting an engine. During the engine startup period, an electric motor/generator supplies a smoothing torque to at least partially cancel engine torque variations.

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.

Methods and controllers for controlling engine speed to reduce NVH that occurs in conjunction with transmission shifts are described. In some embodiments, when a transmission shift to a target gear is expected, a target engine speed appropriate for the target gear is first determined. A target rate of change of the engine speed is calculated from the initial engine speed and target engine speed in conjunction with a target transition time. A target torque is then calculated from the target rate of change of engine speed. A target firing fraction or induction ratio are determined that are desired for use with the target engine speed based on the target torque. The transition to the target engine speed and target firing fraction or induction ratio are completed before the gear shift is completed. The described approaches are well suited for use during skip fire or other cylinder output level modulation operation of the engine.

Methods and controllers for controlling engine speed to reduce NVH that occurs in conjunction with transmission shifts are described. In some embodiments, when a transmission shift to a target gear is expected, a target engine speed appropriate for the target gear is first determined. A target rate of change of the engine speed is calculated from the initial engine speed and target engine speed in conjunction with a target transition time. A target torque is then calculated from the target rate of change of engine speed. A target firing fraction or induction ratio are determined that are desired for use with the target engine speed based on the target torque. The transition to the target engine speed and target firing fraction or induction ratio are completed before the gear shift is completed. The described approaches are well suited for use during skip fire or other cylinder output level modulation operation of the engine.

Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

A variety of methods and arrangements are described for operating an engine in a skip fire manner so that engine requirements, such as exhaust temperature, exhaust flow, torque and NVH, are met.

Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.