Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

One embodiment is a system comprising an internal combustion engine having one or more non-dedicated cylinders and one or more dedicated EGR cylinders configured to provide EGR to the engine via an EGR loop, a first spark plug coupled to each of the one or more non-dedicated cylinders, and a second spark plug coupled to each of the one or more dedicated EGR cylinders, wherein the second spark plug has a physical or dimensional characteristic that is different from the first spark plug. In certain forms each of the non-dedicated cylinders has only one of a first type of spark plug and each of the dedicated EGR cylinders has only one of a second type of spark plug. One or more of the characteristics that may vary between the first and second types of spark plugs include spark gap, electrode diameter, heat range, and ion sensing capability.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors, an ignition system including a plurality of spark plugs, an intake throttle, and an electronic control system. The electronic control system is configured to control combustion during transient operation of the engine by determining one or more combustion control parameters compensating for variation of one or more of inert matter, unburned air and unburned fuel in EGR output by the dedicated EGR cylinder during transient operation of the engine, and an effect of the EGR loop on inert matter, unburned air and unburned fuel provided to the plurality of cylinders, and controlling operation of at least one of the throttle, the ignition system and the plurality of injectors in response to at least one of the one or more combustion control parameters.

An electronic engine timing system that includes at least (1) an engine position sensor that includes a diametric magnet and two or more hall effect sensors configured and positioned to sense diametric magnet position, (2) sensor data receiving circuitry configured for receiving sensory input, including at least input from the engine position sensor; and (3) control circuitry configured to control firing of one or more cylinders of the engine at least in part by calculating one or more timing advance positions for one or more cylinders of the engine and by causing the one or more cylinders to fire according to the one or more calculated timing advance positions, the control circuitry further configured to calculate the one or more timing advance positions for the one or more cylinders separately from one another based at least in part on input from the engine position sensor.

An internal combustion engine with a plurality of cylinders is a drive device in which the drive torque available can be reduced. The ignition timing which is set at the internal combustion engine is adjusted in the retarded direction starting from an initial ignition timing until the ignition timing corresponds to a threshold ignition timing. To reduce the drive torque further, at least one cylinder, among the plurality of cylinders, is deactivated by suspending fuel injection into the cylinder, and the remaining cylinder(s) continue to be operated with fuel injection using the ignition timing. The remaining cylinders of the internal combustion engine which continue to be operated are supplied with a quantity of fuel which is larger in comparison with an initial quantity of fuel present before the cylinder deactivation, to set a substoichiometric fuel/oxygen ratio.

Systems and methods for operating an internal combustion engine that is included in a hybrid vehicle are described. In one example, the internal combustion engine is operated in a two stroke mode during cold starting to increase mass flow to an electrically heated catalyst so that engine emissions may be reduced.

Methods, devices, estimators, controllers and algorithms are described for estimating working chamber air charge during engine operations. The described approaches and devices are well suited for use in dynamic firing level modulation controlled engines. Manifold pressure is estimated for a time corresponding to an induction event associated with a selected working cycle. 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. The estimated manifold pressure is used in the estimation of the air charge for the selected working cycle. The described approach may be used to individually calculate the air charge for each induction event at any time that the engine is operating in a mode that can benefit from the individual cylinder air charge estimations.

A system and method for dynamically varying an amount slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission of a vehicle in response to non-powertrain factors. By varying a slippage output signal, the amount of TCC slippage between the engine and the transmission can be adjusted. Small amounts of slippage, relative to large amounts of slippage, provide (a) improved vehicle fuel economy, but (b) induce more powertrain noise and vibration in the vehicle cabin. By dynamically adjusting the slippage, a tradeoff between improved fuel economy vs. a satisfying driver experience can be realized.

A controller of an engine with a supercharger includes, for each of cylinders, fuel supply system and an ignition plug. The controller includes an electronic control unit that is configured to: (i) set a basic ignition timing depending on an operation state of the engine, (ii) detect, for each cycle, an abnormal combustion generation cylinder in which an abnormal combustion is generated in a supercharged region, (iii) execute a fuel cut to stop a fuel supply by the fuel supply system for the abnormal combustion generation cylinder, (iv) change an ignition timing of the abnormal combustion generation cylinder to expand a crank angle width between a compression top dead center and the basic ignition timing for several cycles after start of the fuel cut, and (v) execute an ignition cut that prohibits a spark from being generated by the ignition plug, further after elapse of the several cycles is executed.

Methods and systems are provided for improving the performance of a variable displacement engine. Split injection and spark retard may be used in active cylinder during a VDE mode to heat an exhaust catalyst and extend the duration of VDE mode operation. Split injection and spark retard may also be used in reactivated cylinders at a time of cylinder reactivation to improve restart combustion stability.