Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.

Abstract: Various methods and systems are provided for adjusting an amount of intake airflow diverted away from an intake manifold and to atmosphere in response to a temperature of exhaust entering a turbocharger turbine and a target pre-turbine temperature. In one example, an amount of intake airflow entering engine cylinders, and thus an air-fuel ratio entering the engine cylinders, may be controlled to maintain the temperature of exhaust entering the turbocharger turbine at the target pre-turbine temperature.

Abstract: An engine control unit of a multi-fuel is provided. The engine consumes a mixture of a first fuel and a second fuel. The engine control unit includes hardware circuitry that includes one or more processors configured to calculate an autoignition delay of the mixture of the air and the second fuel based on current operating conditions of the multi-fuel engine. The one or more processors also are configured to calculate an upper limit on an amount of the second fuel that is supplied to the multi-fuel engine based on the autoignition delay that is calculated.

Abstract: A system detects a parameter and generates a first trip plan to automatically control the vehicle according to a first trip plan. A controller is connected to a sensor and configured to receive the parameter. The controller is configured to generate a new trip plan or modify the first trip plan into a modified trip plan based on at least one of a cumulative damage or an end of life. A new trip plan or the modified trip plan is configured, during operation of the vehicle according to the new trip plan or the modified trip plan, for at least one of an adjustment in velocity or avoiding one or more operating conditions of the vehicle, relative to the first trip plan.

Abstract: Various methods and systems are provided for generating exhaust energy and converting exhaust energy to electrical energy while an engine is not running. In one example, a system for an engine comprises: a first turbocharger including a first compressor driven by a first turbine, the first turbine disposed in an exhaust of the engine; a fuel burner fluidly coupled to the exhaust upstream of the first turbine; a generator coupled to one of the first turbine or an auxiliary, second turbine fluidly coupled to the exhaust downstream of the fuel burner; and one or more bypass valves configured to adjust a flow of air that bypasses the engine and is delivered to the fuel burner.

Abstract: Fuel injector wear methodologies for use with internal combustion engines include a method that determines power of the engine and/or fuel flow of a fuel injector(s) associated with a cylinder the engine; obtains a duration of a fuel injection event from the injector(s) associated with the cylinder(s) of the engine; compares the power, the fuel flow, and/or the duration with a reference value; and then adjusts the fuel injection timing of the fuel injector(s), based on the comparison. Another method adjusts operation of an engine includes: comparing two (or more) engine models, wherein one model is related to a fuel injection event duration of the engine or a modeled fuel quantity being supplied to the engine and then adjusting the fuel injection timing of a fuel injector(s) of the engine, based on the comparison.

Abstract: Various methods and systems are provided for a detecting surge of a turbocharger in an engine system. In one example, system includes a turbocharger including a compressor coupled to a turbine and a controller and sensor system configured to detect a surge event of the turbocharger based on at least one of a rate of change of a pressure measured by sensors downstream of the compressor and a measured rate of change of turbine speed, store operational data associated with the surge event in memory of the controller, and determine a performance of the turbocharger based at least in part on one or more of a cumulative number of detected surge events, a magnitude of detected surge events, or associated operational data.

Abstract: Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to a sensed or estimated intake oxygen fraction by controlling an exhaust gas recirculation (EGR) amount supplied to an engine to maintain a level of particulate matter (PM) in a determined PM range and a level of NOx in a determined NOx range, and adjusting a target intake manifold oxygen fraction or target intake manifold EGR fraction in response to a NOx sensor feedback signal.

Abstract: Various systems are provided for delivering fuel to an engine. In one example, a system includes a controller and a fluid system configured to maintain a fluid at a pressure downstream of a check valve. The controller may be configured to determine if a leak is present in the fluid system based on a first pressure decay rate of the fluid system, and responsive to identifying that a leak is present in the fluid system, differentiate between an internal leak and an external leak based on a leak flow rate as fluid system pressure decreases.

Abstract: A method includes receiving a plurality of signals from a plurality of sensors coupled to a dual fuel engine. The method further includes altering an actual speed of the dual fuel engine to obtain a predetermined air-fuel ratio in response to a changed operating condition of the dual fuel engine determined based on the plurality of signals, so as to maintain operation of the dual fuel engine between knock and misfire conditions.

Abstract: Various systems are provided for delivering fuel to an engine. In one example, a system includes a controller and a fluid system configured to maintain a fluid at a pressure downstream of a check valve. The controller may be configured to determine if a leak is present in the fluid system based on a first pressure decay rate of the fluid system, and responsive to identifying that a leak is present in the fluid system, differentiate between an internal leak and an external leak based on a leak flow rate as fluid system pressure decreases.

Abstract: Various methods for controlling EGR rate are disclosed. In one embodiment, a method comprises routing at least a portion of exhaust from a first exhaust manifold to an intake manifold, and not to atmosphere, the first exhaust manifold exclusively coupled to a first cylinder group. The method further includes routing exhaust from at least one additional exhaust manifold coupled to a corresponding at least one additional cylinder group to atmosphere, and during a first engine operating condition where an engine fuel demand is below a threshold demand, not injecting fuel to each of a subset of cylinders in the first cylinder group while injecting fuel to a subset of all cylinders coupled to the at least one additional exhaust manifold, where a number of cylinders of the subset of cylinders in the first cylinder group decreases in response to an increase in a target EGR rate.

Abstract: Various methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system comprises a first fuel system to deliver liquid fuel to at least one cylinder of an engine, a second fuel system to deliver gaseous fuel to the at least one cylinder, and a controller. The controller is configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder thereby to ignite the liquid fuel and the gaseous fuel in the at least one cylinder via compression-ignition, and adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel.

Abstract: Various methods and systems are provided for estimating fresh intake air flow. In one example, a system comprises an engine having an intake manifold to receive fresh intake air and an exhaust gas recirculation (EGR) system to supply EGR to the intake manifold, where flow of EGR through the EGR system is controlled by one or more exhaust valves. The system further includes a controller configured to adjust a position of the one or more exhaust valves based on an estimated fresh intake air flow rate, where during a first set of operating conditions, the fresh intake air flow rate is estimated based on a total gas flow rate into the engine and further based on a current position of the one or more exhaust valves, intake manifold pressure, air-fuel ratio, and fuel flow to one or more cylinders of the engine.

Abstract: Various methods for controlling EGR rate are disclosed. In one embodiment, a method comprises routing at least a portion of exhaust from a first exhaust manifold to an intake manifold, and not to atmosphere, the first exhaust manifold exclusively coupled to a first cylinder group. The method further includes routing exhaust from at least one additional exhaust manifold coupled to a corresponding at least one additional cylinder group to atmosphere, and during a first engine operating condition where an engine fuel demand is below a threshold demand, not injecting fuel to each of a subset of cylinders in the first cylinder group while injecting fuel to a subset of all cylinders coupled to the at least one additional exhaust manifold, where a number of cylinders of the subset of cylinders in the first cylinder group decreases in response to an increase in a target EGR rate.

Abstract: A method for controlling an engine includes the steps of, in response to a transient operating event, determining a first amount of exhaust gas recirculation (EGR) that if provided to an intake of the engine would avoid turbocharger compressor surge in a turbocharger, determining a second amount of EGR that if provided to the intake would avoid turbocharger compressor choke in the turbocharger, and determining a third amount of EGR that if provided to the intake would avoid engine smoking, and adjusting EGR provided to the intake of the engine in accordance with the determined first, second, and third amounts.

Abstract: Various methods and systems are provided for adjusting an amount of intake airflow diverted away from an intake manifold and to atmosphere in response to a temperature of exhaust entering a turbocharger turbine and a target pre-turbine temperature. In one example, an amount of intake airflow entering engine cylinders, and thus an air-fuel ratio entering the engine cylinders, may be controlled to maintain the temperature of exhaust entering the turbocharger turbine at the target pre-turbine temperature.

Abstract: A method includes controlling an engine speed based on: intake manifold air temperature and/or intake manifold pressure one, or more, of the following data parameters: an engine load as a function of a fuel level, a fuel injecting timing, an intake oxygen concentration, a constituent concentration from the exhaust gas flow, an engine power, and an engine torque. The method also recirculates a portion of the exhaust gas flow to the combustion cylinders of the engine via a recirculation channel, as a function of intake manifold temperature and/or intake manifold pressure at which the engine is operated. An engine system, other methods, and a non-transitory computer readable medium encoded with a program, to enable a processor-based control unit to control aspects of the engine are also disclosed.

Abstract: Various methods and systems are provided for estimating fresh intake air flow. In one example, a system comprises an engine having an intake manifold to receive fresh intake air and an exhaust gas recirculation (EGR) system to supply EGR to the intake manifold, where flow of EGR through the EGR system is controlled by one or more exhaust valves. The system further includes a controller configured to adjust a position of the one or more exhaust valves based on an estimated fresh intake air flow rate, where during a first set of operating conditions, the fresh intake air flow rate is estimated based on a total gas flow rate into the engine and further based on a current position of the one or more exhaust valves, intake manifold pressure, air-fuel ratio, and fuel flow to one or more cylinders of the engine.

Abstract: Various methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system comprises a first fuel system to deliver liquid fuel to at least one cylinder of an engine, a second fuel system to deliver gaseous fuel to the at least one cylinder, and a controller. The controller is configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder thereby to ignite the liquid fuel and the gaseous fuel in the at least one cylinder via compression-ignition, and adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel.