An engine system includes an engine including a plurality of engine cylinders, an intake manifold, and an exhaust manifold; and a compound turbocharger system having a first turbine driving a first compressor, and a second turbine driving a second compressor. The engine system further includes an intake line including the first compressor, the second compressor, and the at least one intake manifold; and an exhaust line including the exhaust manifold, the second turbine, and the first turbine. The engine system also includes an exhaust restriction valve located in the exhaust manifold of the engine downstream of a subset of the plurality of the engine cylinders; and an exhaust gas recirculation line having an upstream end located to receive exhaust from the subset of the plurality of engine cylinders, and a downstream end coupled to the intake line downstream the first compressor and upstream of the second compressor.

A valve assembly includes: a rotary gear being rotated about a vertical central axis that is a rotational axis by force from an outside, and having a non-circular insertion hole on the central axis; a cylindrical cam being able to move up and down while rotating integrally with the rotary gear with an upper end thereof inserted in the insertion hole, and having two or more inclined slide grooves on an outer side thereof; a poppet shaft disposed through the rotational axis of the cylindrical cam to be able to move up and down integrally with and rotate independently from the cylindrical cam; a valve seat coupled to a lower portion of the poppet shaft; a housing and a cover that surround the cylindrical cam; and two or more bearing unit each having a first side fixed to the housing and having second sides respectively inserted in the slide grooves.

A vehicle controller is configured to execute a duty cycle control process of alternately repeating an electric power generation execution period and an electric power generation stop period of an electric generator and controlling a duty cycle, which is a ratio of the electric power generation execution period to a single cycle of repeated cycles, when determining that an anomaly has occurred in a driving circuit. The duty cycle control process includes at least one of two processes, a process of setting the duty cycle to be larger when a member in an overheatable region, in which overheating is possibly performed by the heater, has a low temperature than when the member has a high temperature and a process of setting the duty cycle to be larger when an internal combustion engine has a large intake air amount than when the engine has a small intake air amount.

Methods and systems are provided for an engine. In one example, a method comprises stopping an engine via a soft-stop method in response to a likelihood of condensate forming being less than or equal to a threshold likelihood. The method further comprises stopping the engine via an exhaust gas evacuation method in response to the likelihood of condensate forming being greater than the threshold likelihood.

This diesel engine (10) has an engine body (11), an EGR device (12), and a control unit (13). The engine body (11) has combustion chambers (15) and injectors (16). The EGR device (12) is provided with: a gas flow path (35) that returns a portion of exhaust gas from the combustion chambers (15) to an intake flow path (17); and an EGR device (37) that has a butterfly valve (42). When the butterfly valve (42) is set to a rotation angle position of 0 when in a closed posture (42A), the control unit (13) drives the butterfly valve (42) within a first rotation angle range of no less than 0 when the injection amount of fuel to be injected by the injectors (16) is no less than a predetermined threshold, and the control unit (13) drives the butterfly valve (42) within a second rotation angle range that passes through 0 when the injection amount is less than the threshold. The threshold is a value greater than zero.

Systems and methods for controlling an engine airpath include receiving, at a supervisory controller, an engine speed corresponding to a present engine speed, a fuel target corresponding to a request for torque from a driver and one or more state estimates generated by an estimator. The supervisory controller predicts, over a prediction horizon, a constraint violation in response to the engine speed, the fuel target, and the one or more state estimates using a prediction model, adjusts an EGR rate target to a modified value, when the constraint violation is predicted, and maintains the EGR rate target at a nominal value when the constraint violation is not predicted. A nonlinear predictive controller generates one or more actuator commands based on the EGR rate target, where the one or more actuator commands control an engine actuator such that an EGR rate of the engine airpath tracks the EGR rate target.

An engine system includes an engine including a plurality of engine cylinders, an intake manifold, and an exhaust manifold; and a compound turbocharger system having a first turbine driving a first compressor, and a second turbine driving a second compressor. The engine system further includes an intake line including the first compressor, the second compressor, and the at least one intake manifold; and an exhaust line including the exhaust manifold, the second turbine, and the first turbine. The engine system also includes an exhaust restriction valve located in the exhaust manifold of the engine downstream of a subset of the plurality of the engine cylinders; and an exhaust gas recirculation line having an upstream end located to receive exhaust from the subset of the plurality of engine cylinders, and a downstream end coupled to the intake line downstream the first compressor and upstream of the second compressor.

Methods and systems are provided for reducing exhaust residuals during light load conditions in a split exhaust engine via a check valve. In one example, a scavenge exhaust manifold may be maintained above a threshold pressure by introducing fresh air into the scavenge manifold during a valve overlap period, the scavenge manifold coupled to a cylinder of an engine and coupled to an intake passage of the engine.

Systems and methods for controlling an engine airpath include receiving, at a supervisory controller, an engine speed corresponding to a present engine speed, a fuel target corresponding to a request for torque from a driver and one or more state estimates generated by an estimator. The supervisory controller predicts, over a prediction horizon, a constraint violation in response to the engine speed, the fuel target, and the one or more state estimates using a prediction model, adjusts an EGR rate target to a modified value, when the constraint violation is predicted, and maintains the EGR rate target at a nominal value when the constraint violation is not predicted. A nonlinear predictive controller generates one or more actuator commands based on the EGR rate target, where the one or more actuator commands control an engine actuator such that an EGR rate of the engine airpath tracks the EGR rate target.

An internal combustion engine comprises a supercharger 34 having a compressor 34a and a turbine 34b and an EGR apparatus 50 having an exhaust recirculating pipe 51, an upstream EGR valve 52 and a downstream EGR valve 53. An electronic control unit 60 fully opens the upstream EGR valve 52 and controls an EGR amount by the downstream EGR valve 53 when a peak value of an exhaust pressure increases excessively. Thereby, since exhaust volume increases, the peak value of the exhaust pressure falls. Therefore, damage of parts of an exhaust system can be avoided. The electronic control unit 60 fully opens the downstream EGR valve 53 and controls the EGR amount by the upstream EGR valve 52 when the peak value of the exhaust pressure decreases excessively. Thereby, since the exhaust volume decreases, the peak value of the exhaust pressure rises. Therefore, supercharging can be continued while an EGR gas is being introduced.