Abstract: Methods and systems are provided for diagnosing the presence or absence of a catalyst substrate within a catalyst can or housing. The methods and systems described a persistence of excitation metric that is a basis for judging whether or not the catalyst can is empty. If it is determined that the catalyst can or housing is empty, mitigating control actions may be performed via a controller.

Abstract: Methods and systems are provided for catalyst control. In one example, a method may modulate a downstream catalyst by applying a square waveform to an outer feedback control loop. A fuel adjustment is performed in accordance with the square waveform to create an air-fuel ratio oscillation at an upstream catalyst brick and at a downstream catalyst brick.

Abstract: A method for adjusting boost provided via a turbocharger or supercharger is described. In one example, boost is increased in response to a change in road conditions before a driver reacts to the change in road conditions by applying an accelerator pedal. The boost is increased to reduce compressor lag, thereby increasing the responsiveness of the engine and vehicle.

Abstract: Methods and systems are provided for catalyst control. In one example, a method may modulate a downstream catalyst by applying a square waveform to an outer feedback control loop. A fuel adjustment is performed in accordance with the square waveform to create an air-fuel ratio oscillation at an upstream catalyst brick and at a downstream catalyst brick.

Abstract: Methods and systems are provided for diagnosing the presence or absence of a catalyst substrate within a catalyst can or housing. The methods and systems described a persistence of excitation metric that is a basis for judging whether or not the catalyst can is empty. If it is determined that the catalyst can or housing is empty, mitigating control actions may be performed via a controller.

Abstract: A method for adjusting boost provided via a turbocharger or supercharger is described. In one example, boost is increased in response to a change in road conditions before a driver reacts to the change in road conditions by applying an accelerator pedal. The boost is increased to reduce compressor lag, thereby increasing the responsiveness of the engine and vehicle.

Abstract: A method for compensating for thermal transient conditions of an engine that can cause valve growth or contraction is disclosed. In one example, the method provides cylinder air amount compensation during non-blow-through and blow-through conditions. The approach may improve cylinder air amount estimates, thereby improving engine emissions.

Abstract: An approach is provided for compensating engine fueling during starting conditions in which positive valve overlap is enabled early in the start. In one example, the valve timing is adjusted to increase positive overlap during cold starting conditions, and fuel adjustments are provided to compensate for the evaporation effects of the increased residual push-back.

Abstract: A system, comprising of an internal combustion engine having a combustion chamber with a piston located therein, an intake passage coupled to the combustion chamber, wherein the intake passage supplies intake air to the combustion chamber, an adjustable compressor arranged in the intake passage upstream of the combustion chamber, a throttle arranged in the intake passage upstream of the compressor, and a controller configured to operate the engine so that, at least under some conditions, the piston compresses an air and fuel mixture within the combustion chamber to attain substantial auto-ignition of the mixture; and to increase a boosting of the compressor to increase heating of the intake air, and to decrease the boosting to decrease heating of the intake air, while throttling the intake air with the throttle.

Abstract: An internal combustion engine having a plurality of combustion cylinders and a fuel delivery system. The plurality of combustion cylinders are configured to receive a mixture of gasoline and air and combust such mixture, where some of the combustion cylinders are configured to operate in a spark ignition mode, with the remaining cylinders being configured to operate in a compression ignition mode. The engine may be configured to operate so that fuel vapor purge is added only to cylinders operating in the spark ignition mode. Alternatively, the engine may be operated in either a first purge mode, in which fuel vapor purge is added only to spark ignition cylinders, or a second purge mode, in which fuel vapor purge is added to spark ignition cylinders and compression ignition cylinders.

Abstract: An internal combustion engine having combustion cylinders capable of running on gasoline in either a spark ignition mode or in a homogenous charge compression mode. The allocation of cylinders in each mode is dynamic and may be dynamically controlled and varied during operating of the engine. Also, the engine may include plural aftertreatment systems which may be dynamically selected, typically based on the combustion mode(s) in which the cylinders are operating.

Abstract: A method of operating an engine having at least one cylinder, the method comprising of directing a first air stream to an intake valve of the cylinder; directing a second, separate air stream to a second intake valve of the cylinder, said second air stream at a higher temperature than said first air stream; operating said first intake valve and adjusting at least one of an opening timing and a closing timing of said first intake valve to adjust engine output; and intermittently operating said second intake valve to maintain said higher temperature of said second air stream.

Abstract: A method for controlling valve timing for and engine having adjustable valve timing is presented. In one embodiment, the method allows the intake valve timing to be controlled with respect to exhaust valve timing or the method allows the exhaust valve timing to be controlled with respect to intake valve timing. In addition, the method can bound valve overlap between upper and lower limits so that engine emissions and fuel economy may be improved.

Abstract: A method of operating an engine having at least one cylinder during a homogeneous charge compression ignition is provided. The method comprises: directing a first air stream to the cylinder via a first throttle; directing a second, separate, air stream to the cylinder via a second throttle, said first stream at a higher temperature than said second air stream; regulating a total air flow of a mixture of the first and second streams to a desired value by varying both openings of the first throttle and the second throttle in a same direction; and adjusting compression ignition combustion timing by increasing an opening of one throttle and decreasing an opening of the other throttle.

Abstract: A method of operating an engine having at least one cylinder, the method comprising of directing a first air stream to an intake valve of the cylinder; directing a second, separate air stream to a second intake valve of the cylinder, said second air stream at a higher temperature than said first air stream; operating said first intake valve and adjusting at least one of an opening timing and a closing timing of said first intake valve to adjust engine output; and intermittently operating said second intake valve to maintain said higher temperature of said second air stream.

Abstract: A method for controlling valve timing for and engine having adjustable valve timing is presented. In one embodiment, the method allows the intake valve timing to be controlled with respect to exhaust valve timing or the method allows the exhaust valve timing to be controlled with respect to intake valve timing. In addition, the method can bound valve overlap between upper and lower limits so that engine emissions and fuel economy may be improved.

Abstract: An approach is provided for compensating engine fueling during starting conditions in which positive valve overlap is enabled early in the start. In one example, the valve timing is adjusted to increase positive overlap during cold starting conditions, and fuel adjustments are provided to compensate for the evaporation effects of the increased residual push-back.

Abstract: A system, comprising of an internal combustion engine having a combustion chamber with a piston located therein, an intake passage coupled to the combustion chamber, wherein the intake passage supplies intake air to the combustion chamber, an adjustable compressor arranged in the intake passage upstream of the combustion chamber, a throttle arranged in the intake passage upstream of the compressor, and a controller configured to operate the engine so that, at least under some conditions, the piston compresses an air and fuel mixture within the combustion chamber to attain substantial auto-ignition of the mixture; and to increase a boosting of the compressor to increase heating of the intake air, and to decrease the boosting to decrease heating of the intake air, while throttling the intake air with the throttle.

Abstract: An internal combustion engine having a plurality of combustion cylinders and a fuel delivery system. The plurality of combustion cylinders are configured to receive a mixture of gasoline and air and combust such mixture, where some of the combustion cylinders are configured to operate in a spark ignition mode, with the remaining cylinders being configured to operate in a compression ignition mode. The engine may be configured to operate so that fuel vapor purge is added only to cylinders operating in the spark ignition mode. Alternatively, the engine may be operated in either a first purge mode, in which fuel vapor purge is added only to spark ignition cylinders, or a second purge mode, in which fuel vapor purge is added to spark ignition cylinders and compression ignition cylinders.

Abstract: An internal combustion engine having combustion cylinders capable of running on gasoline in either a spark ignition mode or in a homogenous charge compression mode. The allocation of cylinders in each mode is dynamic and may be dynamically controlled and varied during operating of the engine. Also, the engine may include plural aftertreatment systems which may be dynamically selected, typically based on the combustion mode(s) in which the cylinders are operating.