Abstract: A method includes operating an engine system including a plurality of cylinders, a plurality of fuel injectors configured to provide fuel the plurality of cylinders, a compression braking system configured to selectably brake at least a first set of the plurality of cylinders, and an exhaust aftertreatment system including at least one catalyst. The method includes determining a condition for brake-fuel operation and, in response to the act of determining, operating the engine in a brake-fuel mode wherein the compression brake is actuated to provide compression braking of the first set of the plurality of cylinders and a second set of the plurality of cylinders receives and combust fuel provided from respective ones of the plurality of fuel injectors.

Abstract: A system comprising an actuator and a controller configured to drive the actuator with a pulse width modulated (PWM) signal. The controller is configured to limit a duty cycle of the PWM signal in response to a current supplied by the PWM signal.

Abstract: A system for controlling turbocharger compressor surge includes a turbocharger compressor fluidly coupled to an engine intake manifold, an exhaust gas recirculation (EGR) valve disposed in-line with an EGR conduit fluidly coupled between the engine intake and exhaust manifolds, means for determining a mass flow parameter, a speed sensor producing a speed signal indicative of turbocharger speed, and a control computer configured to determine a mass flow rate surge value, corresponding to a fresh air mass flow rate above which turbocharger compressor surge is avoided, as a function of the speed signal, and to limit the EGR valve position and VGT position as a function of the mass flow parameter and the mass flow rate surge value to maintain exhaust gas flow through the EGR valve at a flow rate below which turbocharger compressor surge is avoided.

Abstract: A system for estimating engine exhaust pressure includes a pressure sensor fluidly coupled to an intake manifold of the engine, a turbocharger having a turbine fluidly coupled to an exhaust manifold of the engine, a control actuator responsive to a control command to control either of a swallowing capacity and a swallowing efficiency of the turbine, and a control computer estimating engine exhaust pressure as a function of the pressure signal and the control command. In an alternate embodiment, the system includes an engine speed sensor, an EGR valve fluidly connected between the intake manifold and the exhaust manifold, and an EGR valve position sensor. The control computer is operable in this embodiment to estimate engine exhaust pressure as a function of the pressure signal, the control command, the engine speed signal and the EGR valve position signal.

Abstract: A system for estimating engine exhaust pressure includes a pressure sensor fluidly coupled to an intake manifold of the engine, a turbocharger having a turbine fluidly coupled to an exhaust manifold of the engine, a control actuator responsive to a control command to control either of a swallowing capacity and a swallowing efficiency of the turbine, and a control computer estimating engine exhaust pressure as a function of the pressure signal and the control command. In an alternate embodiment, the system includes an engine speed sensor, an EGR valve fluidly connected between the intake manifold and the exhaust manifold, and an EGR valve position sensor. The control computer is operable in this embodiment to estimate engine exhaust pressure as a function of the pressure signal, the control command, the engine speed signal and the EGR valve position signal.