Methods and systems for providing exhaust gas recirculation to a two stroke opposed piston diesel engine are described. In one example, high and low pressure exhaust gas recirculation systems may be activated or deactivated in response to exhaust gas hydrocarbon concentration and particulate matter flow rate from the engine. In addition, operation of the low and high pressure exhaust gas recirculation systems may be responsive to an operating state of a supercharger compressor.

Methods and systems are provided for adjusting a throttle based on an intake oxygen sensor output. In one example, a method may include adjusting a position of a throttle based on a dilution threshold and a total aircharge dilution level, the total dilution aircharge level based on an output of an intake oxygen sensor. Additionally, spark timing may be adjusted based on the total aircharge dilution level.

Methods and systems are provided for operating an electric assisted turbocharger. In one example, a method may include adjusting a position of a turbine of the turbocharger responsive to a level of a power deficiency, and operating an electric motor of the turbocharger based on the power deficiency.

Methods and systems are provided for measuring exhaust gas recirculation (EGR) distribution among individual engine cylinders. In one example, a method may include fluidly coupling a plurality of intake runners of an engine to a vacuum pump, diverting a portion of intake charge gas from the intake runner to a gas composition sensor with the vacuum pump, measuring an oxygen concentration of the diverted intake charge portion with the gas composition sensor, and estimating an EGR concentration of the intake charge based on the measured oxygen concentration.

Provided is a control device for an internal combustion engine, which can ensure a stable combustion state of the internal combustion engine even under a high-humidity environment condition, thereby improving the merchantability. The control device for the internal combustion engine includes an ECU (electronic control unit). The ECU calculates a basic target EGR amount according to an operating state of the internal combustion engine, calculates a water vapor amount in air drawn into an intake passage of the internal combustion engine, calculates an EGR conversion amount by using the water vapor amount, calculates a target EGR amount by subtracting the EGR conversion amount from the basic target EGR amount, and controls internal EGR and external EGR of the internal combustion engine by using the target EGR amount.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary exhaust gas recirculation (EGR) cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the fueling to the at least one primary EGR cylinder in response to EGR fraction reduction conditions.

According to one aspect of the present disclosure, a method of controlling an exhaust gas recirculation (EGR) system of an engine system includes determining a first EGR command according to a first method during a steady state engine condition, determining a second EGR command according to a second method during a transient engine condition, wherein the first method is based at least in part on values from a NOx sensor, and the second method is not based on values from a NOx sensor. The method further includes adjusting an EGR valve of the EGR system based on the first EGR command during the steady state engine condition, and adjusting the EGR valve based on the second EGR command during the transient engine condition.

Methods and systems are provided for cleaning an exhaust particulate filter by routing air via the exhaust particulate filter during a vehicle-off condition. In one example, during vehicle-off conditions, a turbocharger may be reverse rotated via an electric motor or an engine may be reverse rotated via an electric machine to route air via the exhaust particulate filter and the soot collected from the particulate filter may then be deposited on an air filter coupled to the intake manifold. During a subsequent engine start, the soot from the intake air filter may be routed to the engine cylinders for combustion.

A novel control device for an internal combustion engine capable of highly accurately estimating an EGR amount (rate) during the transient state is provided. A first EGR rate is determined using, as an input, a detection signal of an EGR sensor provided on the downstream side of a throttle valve which adjusts the flow rate of a mixed gas of air and EGR gas flowing through an intake pipe, a second EGR rate is estimated by calculating a predetermined equation using, as an input, at least a detection signal of an air flow sensor and an EGR valve opening degree sensor, a third EGR rate is determined by carrying out delay processing on the second EGR rate corresponding to a response delay of the EGR sensor, and the second EGR rate is subjected to learning correction by reflecting a difference between the third EGR rate and the first EGR rate.

According to one aspect of the present disclosure, a method of controlling an exhaust gas recirculation (EGR) system of an engine system includes determining a first EGR command according to a first method during a steady state engine condition, determining a second EGR command according to a second method during a transient engine condition, wherein the first method is based at least in part on values from a NOx sensor, and the second method is not based on values from a NOx sensor. The method further includes adjusting an EGR valve of the EGR system based on the first EGR command during the steady state engine condition, and adjusting the EGR valve based on the second EGR command during the transient engine condition.