Abstract: A method to control an exhaust gas recirculation and a manifold air pressure in an engine includes utilizing a decoupling matrix within a multiple input and multiple output controller to determine an exhaust gas recirculation command and a manifold air pressure command, wherein the decoupling matrix is configured based upon a diagonally dominant model of the engine compensated by the determined exhaust gas recirculation command and the manifold air pressure command. The exhaust gas recirculation and manifold air pressure are controlled based upon the determined exhaust gas recirculation command and the determined manifold air pressure command.

Abstract: An engine is fueled with a fuel blend of diesel and bidiesel fuel. A feed forward fuel control term is provided corresponding to a 100 percent diesel fuel blend and a feedback fuel control term corrects for lambda deviations resulting in a final fuel control term. During regeneration of a lean Nox trap, the feed forward fuel control term is adapted with a factor as a function of the feed forward fuel control term and the final fuel control term.

Abstract: A method to control an internal combustion engine includes operating the engine with a fuel blend of a first fuel and a second fuel, monitoring a value of a first combustion parameter during engine operation, monitoring a first value for a second combustion parameter during engine operation, determining a second value for the second combustion parameter in accordance with a predetermined correspondence among the first combustion parameter, the second combustion parameter, and a predetermined fuel blend of the first fuel and the second fuel, determining the fuel blend based upon a difference between the first and second values for the second combustion parameter, and controlling the engine based upon the fuel blend.

Abstract: A compression-ignition engine is coupled to an exhaust aftertreatment system including a particulate filter. A method of operating the compression-ignition engine includes executing a feed-forward control scheme to determine an amount of post-combustion fuel to achieve a preferred temperature in the exhaust gas feedstream at an inlet to the particulate filter. The amount of post-combustion fuel is a nominal post-combustion fuel amount adjusted for a biodiesel blend ratio of the fuel. The post-combustion fuel is injected upstream of the exhaust aftertreatment system in response to a command to regenerate the particulate filter.

Abstract: A method for operating a compression-ignition engine includes controlling an engine fueling, a compressor boost pressure, and an EGR content in a cylinder charge to maintain engine operation in response to a biodiesel blend ratio of a biodiesel fuel blend.

Abstract: Methods and systems for detecting faults with nitrogen oxides sensors used to detect the presence of nitrogen oxides in an exhaust effluent gas stream emitted from a combustion engine during its operation include providing a virtual nitrogen oxides sensor measurement compared with actual nitrogen oxides content measured by nitrogen oxides sensors.

Abstract: A method for determining a cylinder air charge for an internal combustion engine includes determining engine operating parameters including an intake air charge density, an engine delta pressure as a ratio of an intake manifold pressure to an exhaust pressure, and an engine speed. An open-throttle volumetric efficiency corresponding to the engine operating parameters is determined, and a closed-throttle volumetric efficiency corresponding to the engine operating parameters is also determined. The cylinder air charge is determined using a selected one of the open-throttle volumetric efficiency and the closed-throttle volumetric efficiency.

Abstract: A method and system for adaptively controlling a diesel engine to account for variations in the cetane number of the diesel fuel being used. An engine controller includes various control modules with algorithms for estimating the fuel cetane number, or determining the ignition delay that the engine is experiencing, or both. With this information, the controller can adjust the amount of exhaust gas recirculation that is used, thus varying the amount of oxygen that is available in the intake charge to burn the fuel. The controller can also adjust the timing of the fuel injection event, as another way of altering the nature of combustion. Using these techniques, the controller can optimize the engine operation based on the fuel currently being used.

Abstract: A method for estimating a cylinder air charge for an internal combustion engine includes determining a first volumetric efficiency corresponding to engine operation with an open exhaust gas recirculation valve, determining a second volumetric efficiency corresponding to engine operation with a closed exhaust gas recirculation valve, determining a cylinder air charge using a selected one of the first and second volumetric efficiencies.

Abstract: A method for controlling combustion in a direct injection internal combustion engine operable in a lean combustion mode includes monitoring in-cylinder pressure, utilizing a time-based filter to calculate an actual combustion noise based upon the monitored in-cylinder pressure, monitoring combustion control parameters utilized by the engine, determining an expected combustion noise based upon the monitored combustion control parameters, comparing the actual combustion noise to the expected combustion noise, and adjusting the combustion control parameters based upon the comparing.

Abstract: Combustion pressure in a diesel combustion chamber is monitored to determine a combustion parameter as a function of the monitored pressure. A cetane number of the fuel combusted is determined as a function of a predetermined correlation between the combustion parameter and the cetane number.

Abstract: A method for adjusting fuel injection timing in an internal combustion engine including a cylinder and configured to operate multiple fuel injections in the cylinder per combustion cycle includes monitoring in-cylinder pressure through a first combustion cycle, determining actual combustion phasing metrics based upon the in-cylinder pressure, monitoring a baseline fuel injection timing comprising a first injection timing and a second injection timing, providing expected combustion phasing metrics based upon the baseline fuel injection timing, comparing the actual combustion phasing metrics to the expected combustion phasing metrics, and adjusting the baseline fuel injection timing in a second combustion cycle based upon the comparing.

Abstract: An engine includes an intake manifold mixing an intake air flow and an exhaust gas recirculation flow to provide an intake charge flow. A method to estimate an intake charge temperature of the intake charge includes monitoring system conditions for the engine, determining an effect of the mixing upon a specific heat coefficient of the intake charge flow based upon the monitored system conditions, estimating the intake charge temperature based upon the effect of the mixing upon the specific heat coefficient of the intake charge flow and the monitored system conditions, and controlling the engine based upon the estimated intake charge temperature.

Abstract: An engine is fueled with a fuel blend of diesel and bidiesel fuel. A feed forward fuel control term is provided corresponding to a 100 percent diesel fuel blend and a feedback fuel control term corrects for lambda deviations resulting in a final fuel control term. During regeneration of a lean Nox trap, the feed forward fuel control term is adapted with a factor as a function of the feed forward fuel control term and the final fuel control term.

Abstract: A method to control an internal combustion engine includes operating the engine with a fuel blend of a first fuel and a second fuel, monitoring a value of a first combustion parameter during engine operation, monitoring a first value for a second combustion parameter during engine operation, determining a second value for the second combustion parameter in accordance with a predetermined correspondence among the first combustion parameter, the second combustion parameter, and a predetermined fuel blend of the first fuel and the second fuel, determining the fuel blend based upon a difference between the first and second values for the second combustion parameter, and controlling the engine based upon the fuel blend.

Abstract: A method for estimating a cylinder air charge for an internal combustion engine includes determining a first volumetric efficiency corresponding to engine operation with an open exhaust gas recirculation valve, determining a second volumetric efficiency corresponding to engine operation with a closed exhaust gas recirculation valve, determining a cylinder air charge using a selected one of the first and second volumetric efficiencies.

Abstract: A method for determining a cylinder air charge for an internal combustion engine includes determining engine operating parameters including an intake air charge density, an engine delta pressure as a ratio of an intake manifold pressure to an exhaust pressure, and an engine speed. An open-throttle volumetric efficiency corresponding to the engine operating parameters is determined, and a closed-throttle volumetric efficiency corresponding to the engine operating parameters is also determined. The cylinder air charge is determined using a selected one of the open-throttle volumetric efficiency and the closed-throttle volumetric efficiency.

Abstract: A direct-injection, compression-ignition internal combustion engine control adapts nominal minimum pulsewidth parameters controlling the fuel injectors to minimize pilot fuel delivered to the cylinders required to initiate a preliminary combustion event.

Abstract: A method for diagnosing combustion within a direct-injection, internal combustion engine including a plurality of combustion chambers and operative lean of stoichiometry includes monitoring pressure readings in the plurality of combustion chambers across engine crank angles, estimating a mass fraction burn percentage for each pressure reading, determining respective crank angles corresponding to a predetermined mass burn percentage for each combustion chamber, comparing said determined crank angles for sequential ones of the plurality of combustion chambers, and indicating an abnormal combustion event if compared crank angles differ by a predetermined angle.

Abstract: A method for estimating an oxygen concentration in an intake manifold of a diesel engine utilizing exhaust gas recirculation includes monitoring engine operation, monitoring an exhaust gas recirculation valve, and monitoring an exhaust air fuel ratio. When the engine operates in steady state with the exhaust gas recirculation valve in the closed position, a volumetric efficiency for the engine is updated. A partial pressure due to exhaust gas recirculation within the intake manifold based upon the updated volumetric efficiency is determined, and an estimated oxygen concentration within the intake manifold based upon the partial pressure due to exhaust gas recirculation within the intake manifold and the exhaust air fuel ratio is determined. Operation of the engine is controlled based upon the estimated oxygen concentration within the intake manifold.