Abstract: A system and method for dynamically deactivating engine cylinders of an engine equipped with a cylinder deactivation system, where the system and method control torsional vibration in the engine while deactivating cylinders using a computer programed with a desired firing density and a controlled range of engine vibration frequencies. The computer dynamically determines a cylinder firing pattern that provides the desired firing density while optimizing a cost function norm in the controlled range of engine vibration frequencies. The cylinder deactivation system in the engine is then controlled using the determined cylinder firing pattern.

Abstract: A system and method for improving the functioning of a turbocharged diesel engine equipped with a cylinder deactivation system includes detecting when the turbocharged diesel engine is at risk of compressor surge, and then delaying the implementation of the cylinder deactivation. The delay may be a set period of time, or it may be determined by performing a set of instructions effective for estimating changes in intake manifold pressures over time if cylinders are deactivated, and then comparing the intake manifold pressure estimates to acceptable intake manifold pressure information. A formula for performing the required estimates is provided.

Abstract: Increasing engine idle speed, combined with modulating the timing of the exhaust valve during idling, increases heat transfer from the engine to aftertreatment systems to reduce the time required for the aftertreatment system to reach a minimum temperature for efficient operation. The resultant increases in heat transfer include an increase of at least 30% in the flow rate of exhaust gases and an increase of exhaust temperature by at least 25° C.

Abstract: Increasing engine idle speed, combined with modulating the timing of the exhaust valve during idling, increases heat transfer from the engine to aftertreatment systems to reduce the time required for the aftertreatment system to reach a minimum temperature for efficient operation. The resultant increases in heat transfer include an increase of at least 30% in the flow rate of exhaust gases and an increase of exhaust temperature by at least 25° C.

Abstract: A system and method for improving the functioning of a turbocharged diesel engine equipped with a cylinder deactivation system includes detecting when the turbocharged diesel engine is at risk of compressor surge, and then delaying the implementation of the cylinder deactivation. The delay may be a set period of time, or it may be determined by performing a set of instructions effective for estimating changes in intake manifold pressures over time if cylinders are deactivated, and then comparing the intake manifold pressure estimates to acceptable intake manifold pressure information. A formula for performing the required estimates is provided.

Abstract: An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves, an aftertreatment system to treat exhaust emission from the engine, and a controller coupled to at least one sensor and configured to control a cam phaser for thermal management of the aftertreatment system.

Abstract: Advanced combustion modes, such as PCCI, operate near the system stability limits. In PCCI, the combustion event begins without a direct combustion trigger in contrast to traditional spark-ignited gasoline engines and direct-injected diesel engines. The lack of a direct combustion trigger encourages the usage of model-based controls to provide robust control of the combustion phasing. The nonlinear relationships between the control inputs and the combustion system response often limit the effectiveness of traditional, non-model-based controllers. Accurate knowledge of the system states and inputs is helpful for implementation of an effective nonlinear controller. A nonlinear controller is developed and implemented to control the engine combustion timing during diesel PCCI operation by targeting desired values of the in-cylinder oxygen concentration, pressure, and temperature during early fuel injection.

Abstract: A system and method are provided for monitoring a pressure of fuel supplied to the fuel injector, and providing a control input voltage to the piezostack in response to the pressure to cause the injector to provide a fuel injection having a desired shape. In the system and method, providing a control input voltage includes applying a model-based algorithm to the pressure to determine the control input voltage.

Abstract: A system and method are provided for monitoring a pressure of fuel supplied to the fuel injector, and providing a control input voltage to the piezostack in response to the pressure to cause the injector to provide a fuel injection having a desired shape. In the system and method, providing a control input voltage includes applying a model-based algorithm to the pressure to determine the control input voltage.

Abstract: Advanced combustion modes, such as PCCI, operate near the system stability limits. In PCCI, the combustion event begins without a direct combustion trigger in contrast to traditional spark-ignited gasoline engines and direct-injected diesel engines. The lack of a direct combustion trigger encourages the usage of model-based controls to provide robust control of the combustion phasing. The nonlinear relationships between the control inputs and the combustion system response often limit the effectiveness of traditional, non-model-based controllers. Accurate knowledge of the system states and inputs is helpful for implementation of an effective nonlinear controller. A nonlinear controller is developed and implemented to control the engine combustion timing during diesel PCCI operation by targeting desired values of the in-cylinder oxygen concentration, pressure, and temperature during early fuel injection.

Abstract: A physically-based, generalizable method to estimate the in-cylinder oxygen fraction from production viable measurements or estimates of exhaust oxygen fraction, fresh air flow, charge flow, fuel flow, turbine flow and EGR flow. The oxygen fraction estimates can be sensitive to errors in the EGR and turbine flow, and in other embodiments, a high-gain observer is implemented to improve the estimate of EGR flow. The observer is applicable to engines utilizing high pressure cooled exhaust gas recirculation, variable geometry turbocharging and flexible intake valve actuation as well as other engines.