Abstract: Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection 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. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Abstract: Methods and systems are provided for a multi-fuel engine. In one example, a method includes operating engines of rail vehicles at a desired substitution ratio to recharge an energy storage device of a rail vehicle operating in an all-electric mode to meet a requested total power.

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: An engine control unit of a multi-fuel is provided. The engine consumes a mixture of a first combustion fuel and a second combustion 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 combustion 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 combustion fuel that is supplied to the multi-fuel engine based on the autoignition delay that is calculated.

Abstract: Methods and systems are provided for a turbocharger. In one example, a method includes adjusting one or more of a wastegate position and a position of vanes with operation of a turbocharger to reach a desired turbocharger speed via a controller. The method further includes adjusting engine operating parameters to reach the desired turbocharger speed.

Abstract: A method is provided for controlling an engine. In one example, the method may include injecting fuel to the engine; and during an operating condition, limiting injected fuel based on engine airflow to a smoke-fuel limit, the smoke-fuel limit transiently adjusted from a first smoke-fuel limit to a second smoke-fuel limit based on a duration operating at the smoke-fuel limit. In one example, the method may include during another operating condition, fuel injection not limited by the smoke-fuel limit. In some examples, the duration may be a time duration. In some examples, the duration may be a crank angle duration. In some examples, limiting the injected fuel is based on an estimated engine airflow and estimated fuel injection amount to the engine.

Abstract: Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection 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. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Abstract: Systems and methods are provided for diagnosing cylinders. In one example, a system includes an engine having a plurality of cylinders coupled to a crankshaft, a crankshaft speed sensor, and a controller. The controller is configured to receive a first output from the crankshaft speed sensor during nominal engine operation, receive a second output from the crankshaft speed sensor during engine operation where a fueling disturbance is introduced to a cylinder of the plurality of cylinders, indicate that the cylinder is unhealthy responsive to a difference between the first output and the second output being less than a threshold difference, and adjust one or more operating parameters of the engine in response to the indication.

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: A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

Abstract: Various methods and systems are provided for dynamically assigning cylinders to cylinder sets in engines having two or more cylinder banks, wherein each cylinder bank is fed intake air by a separate intake manifold, and wherein each cylinder bank includes a separate exhaust manifold. In one example, the current disclosure teaches comparing engine operating conditions against a plurality of predetermined override conditions, and responding to the engine operating conditions matching a predetermined override condition of the plurality of predetermined override conditions by reassigning at least a first cylinder of a first cylinder bank from a first cylinder set to a second cylinder set, and adjusting an operating parameter of the second cylinder set and first cylinder set based on the override condition. In this way, cylinders may be dynamically assigned to cylinder sets based, from a default cylinder set, based on occurrence of predetermined override conditions.

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: Methods and systems are provided for controlling fueling and mitigating knock in internal combustion engines, such as multi-fuel engines. In one example, a method may include monitoring a frequency of knock events corresponding to one or more engine cylinders, and dynamically increasing a substitution ratio while the frequency of knock events is less than a maximum action threshold. In some examples, the method may further include actively adjusting one or more engine operating conditions to decrease the substitution ratio responsive to a severity of knocking in the one or more engine cylinders being greater than or equal to a threshold severity.

Abstract: Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to one or more of intake manifold air temperature (MAT), intake air flow rate, or a sensed or estimated intake oxygen fraction by changing an exhaust gas recirculation (EGR) amount to maintain particulate matter (PM) and NOx within a range, and then further adjusting the EGR amount based on NOx sensor feedback.

Abstract: A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

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 date. 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 controlling emissions. In one example, a controller is configured to respond to a sensed exhaust oxygen concentration by changing a fuel injection timing to maintain particulate matter (PM) within a range, and then adjusting an exhaust gas recirculation (EGR) amount based on NOx sensor output and based on the change in fuel injection timing.

Abstract: Various methods and systems are provided for dynamically assigning cylinders to cylinder sets in engines having two or more cylinder banks, wherein each cylinder bank is fed intake air by a separate intake manifold, and wherein each cylinder bank includes a separate exhaust manifold. In one example, the current disclosure teaches comparing engine operating conditions against a plurality of predetermined override conditions, and responding to the engine operating conditions matching a predetermined override condition of the plurality of predetermined override conditions by reassigning at least a first cylinder of a first cylinder bank from a first cylinder set to a second cylinder set, and adjusting an operating parameter of the second cylinder set and first cylinder set based on the override condition. In this way, cylinders may be dynamically assigned to cylinder sets based, from a default cylinder set, based on occurrence of predetermined override conditions.

Abstract: Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection 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. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Abstract: Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection 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. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.