Abstract: A method for controlling intake manifold oxygen for an engine having a fresh air inlet and an exhaust gas recirculation (EGR) circuit includes the steps of: establishing an ideal excess oxygen ratio for combustion in the engine; calculating a total mass flow of oxygen to be delivered to an intake manifold of the engine to maintain the ideal excess oxygen ratio; determining a mass flow of EGR oxygen in the mass flow of EGR gas; and controlling a desired mass flow of fresh oxygen to be delivered to the intake manifold such that the sum of the desired mass flow of fresh oxygen and the mass flow of EGR oxygen is equal to the desired total mass flow of oxygen, by re-adjusting the EGR valve.

Abstract: In an exhaust gas recirculation system for an internal combustion engine, which includes a turbocharger; a high-pressure EGR unit; a low-pressure EGR unit; a high-pressure EGR valve; and a low-pressure EGR valve, first, the opening amount of the high-pressure EGR valve is controlled in a feedback manner, and, then, the opening amount of a low-pressure EGR valve is controlled in a feedback manner in a transitional operation period in which the operation mode of the internal combustion engine is changing. In this way, the intake air amount is promptly adjusted to the target intake air amount without causing hunting.

Abstract: An electropneumatic converter for connection with an exhaust recirculation valve in a motor vehicle. The electropneumatic converter includes a vacuum port and an atmospheric pressure port configured to connect with a valve chamber using a valve device, wherein a mixed pressure is formed in the valve chamber and supplied to a mixed pressure port. An armature is affixed to a valve body of the valve device movable in an axial direction, the valve body being connected to a suspension device, wherein the armature is displaceable in the axial direction using a solenoid. The electropneumatic converter also includes a damping element configured to dampen the axial movement of the armature and the valve device affixed thereto. The damping element includes at least one of an elastomer or a foamed material.

Abstract: An inner surface of an exhaust gas passage 22 of an EGR valve 11 is coated with Teflon coating 31 and a surface of a valve rod 25 is coated with a film 32 of chromium plating.

Abstract: A combustion system for a vehicle may include a piston in which a first combustion recess is formed in an upper end surface thereof, and at least one second combustion recess is further formed at the bottom of the first combustion recess, a first intake port and a second intake port for supplying a cylinder with air, and a controller that differently controls amounts of recirculation exhaust gas being supplied to the first intake port and the second intake port.

Abstract: An exhaust system for a turbocharged internal combustion engine comprises a first exhaust conduit extending between a first engine cylinder and a turbocharger inlet and is configured to conduct exhaust gas therebetween. A second exhaust conduit extends between a second engine cylinder and an in inlet for an exhaust gas recirculation system and is configured to conduct exhaust therebetween. An exhaust gas bypass extends between, and is in fluid communication with, the first and second exhaust conduits and is configured to divert exhaust gas flowing through the second exhaust gas conduit to the first exhaust gas conduit, and the turbocharger inlet, under conditions of varying exhaust gas recirculation demand of the internal combustion engine.

Abstract: An exhaust gas recirculation control system for internal combustion engines includes an intake pipe (1) for delivering combustion air to the individual combustion chambers, an exhaust pipe (2) for discharging the exhaust gases from the combustion chambers, an exhaust gas recirculation line (3) that connects the intake pipe (1) and the exhaust pipe (2), and a mechanical injection pump (4) which is controlled by a control rod (5) is disclosed. An electrically controlled EGR valve (exhaust gas recirculation valve) (6) is located in the exhaust gas recirculation line (3) in order to control the effective cross section of the exhaust gas recirculation line (3) while an electrical pick-off device (7) determines the position of the control rod (5) and then controls the EGR valve (6).

Abstract: A method for charging an intake manifold of an engine comprises adjusting an LP EGR flow rate and an uncooled HP EGR flow rate within first limits to maintain a target dilution level in the intake manifold at steady-state. The method further comprises adjusting the LP EGR and uncooled HP EGR rates within second limits, different from the first, to maintain the target dilution level in the intake manifold during transient conditions.

Abstract: An exhaust gas recirculation system has an EGR valve disposed in an EGR duct connecting an engine intake and exhaust. A diaphragm of said EGR valve is actuated via vacuum from the engine intake, the application of the vacuum is controlled via an electronic valve regulator (EVR). The EVR is provided a fixed signal to cause it to be fully open when it is determined that the engine is about to encounter a condition in which there is insufficient vacuum to open the EGR valve. The EVR is provided a variable signal during other operating conditions in which there is sufficient vacuum to open the EGR valve.

Abstract: A system and method for delivering EGR to an internal combustion engine is presented. The system can reduce system cost and lower system complexity.

Abstract: A method is provided for operating an internal combustion engine of a motor vehicle. The method includes, but is not limited to storing exhaust gas while the engine is working, and supplying the stored exhaust gas into at least an engine cylinder during a subsequent start phase of the engine.

Abstract: Systems and methods are provided for operating an engine exhaust system. In one example, a system comprises a first valve, and a second valve coupled to the first valve via a shaft. A first position of the shaft situates the first valve closed and the second valve open, a second position situates the second valve closed and the first valve open by a first amount, and a third position situates the second valve closed and the first valve open by a second, larger amount.

Abstract: An engine control system for a homogeneous charge compression ignition (HCCI) engine includes a position determination module, a position correction module, and a valve control module. The position determination module determines an initial position of an exhaust gas recirculation (EGR) valve based on a predetermined function of a desired EGR flow, intake manifold pressure, exhaust manifold pressure, and exhaust gas temperature. The position correction module determines a position correction for the EGR valve based on pressure in a cylinder of the HCCI engine. The valve control module commands the EGR valve to the initial position during a transition from spark ignition (SI) combustion to HCCI combustion, and commands the EGR valve to a final position within a predetermined period after the transition, wherein the final position includes a sum of the initial position and the position correction.

Abstract: A method for operating an engine with a fuel reformer is presented. In one embodiment a first fuel is reformed into a gaseous fuel comprising H, CO, and CH4. The engine is operated by injecting the gaseous fuel and a second fuel to a cylinder of the engine in response to an available amount of gaseous fuel, engine speed and engine load. Further, an engine actuator may be adjusted to vary cylinder charge in response to the available amount of gaseous fuel.

Abstract: An engine system comprises an air cleaner, a combustion chamber coupled to an intake port, and an intake manifold. The intake manifold is configured to receive air from the air cleaner, and, under some conditions to receive exhaust from the combustion chamber. The engine system further comprises a multifunction, barrel-type throttle valve coupled to the intake port via an outlet, the throttle valve having a first inlet coupled to the intake manifold and a second inlet coupled to the air cleaner.

Abstract: A valve having a valve body with an inlet port and an outlet port and a valve disposed between the inlet port and outlet port. A sensor is operably associated with the valve and the valve body, and measures a characteristic in proximity to the valve. The sensor communicates information regarding said characteristic to a control unit that sends position commands to said valve.

Abstract: In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.

Abstract: While an engine (10, 10A, 10B, 10C, 10D, 10E) is operating, a control system (22) processes data for certain engine operating parameters to calculate a quantity of exhaust gas needed to satisfy an exhaust gas recirculation requirement. If a primary EGR control loop (34) alone can satisfy the calculated quantity of exhaust gas, a secondary EGR control loop (36) is closed while the primary EGR control loop is controlled to satisfy the calculated quantity. When the processing determines that the primary EGR control loop alone cannot satisfy the calculated quantity, the secondary EGR control loop is open concurrently with the primary EGR control loop and both the primary EGR loop and the secondary EGR loop are controlled to cause the combined flow of exhaust gas through the primary EGR control loop and flow of exhaust gas through the secondary EGR control loop to satisfy the calculated quantity.

Abstract: An object of the present invention is to provide a technology that enables to enhance the effect of decreasing the NOx emission achieved by an exhaust gas purification system as a whole while favorably achieving both reduction in the amount of NOx generated in an internal combustion engine by means of EGR and reduction reaction of NOx in an NOx catalyst even when a reduction process for the NOx catalyst is performed while EGR is being performed. In the invention, in the case where addition of fuel into an exhaust pipe from a fuel addition valve 28 is performed to carry out the reduction process for the NOx catalyst 20 when EGR is being performed mainly by means of a low pressure EGR passage 23, the amount of the exhaust gas passing through the NOx catalyst 20 is decreased by decreasing the amount of the exhaust gas recirculated by the low pressure EGR passage 23.

Abstract: A method and apparatus for improving recirculation of exhaust gas in an internal combustion engine having an exhaust-gas turbocharger, in particular in a diesel engine, determines operation parameters of the engine in order to determine exhaust gas pressures, supplies compressed air in a controlled manner based on the exhaust gas pressures in order to generate a vacuum in a supply section of a gas supply device, thereby inducting a partial quantity of exhaust gas from the engine into the supply section using the vacuum, and recirculates the partial quantity of exhaust gas into the engine via an induction line connected to the gas supply device.

Abstract: An air breathing fuel consuming internal combustion engine with EGR and a control for the quantity of EGR. The total gas flow of the engine is calculated by measuring temperature and pressure at the intake to the engine. The fresh air flow is measured by an orifice or venturi at any point in the flow path for fresh air for combustion by the engine prior to the introduction of the EGR flow. The difference between the calculated total flow and fresh air flow is the actual EGR flow which is used to set the EGR relative to total flow according to one of a number of selected control algorithms.

Abstract: An internal combustion engine having an engine block for internal combustion, a high-pressure (HP) turbocharger for delivering pressurized intake air to the engine block, a low-pressure (LP) turbocharger for delivering pressurized intake air to the HP turbocharger, a turbogenerator for recovering heat energy from the exhaust gas downstream of the LP turbocharger to generate electricity, and an exhaust gas recirculation (EGR) system comprising an EGR-pump drawing exhaust gas from an EGR inlet located downstream of the turbogenerator, wherein the EGR-pump controllably delivers exhaust gas to an EGR mixer in the pressurized intake air stream at a location between the LP turbocharger and HP turbocharger. An electronic control unit (ECU) is adapted to command the EGR-pump to deliver a desired EGR flow-rate to the engine block based on look-up tables and either open-loop and/or closed-loop control algorithms.

Abstract: An internal combustion engine defined as having an engine block for internal combustion, a high-pressure turbocharger for delivering pressurized intake air to the engine block, a low-pressure turbocharger for delivering pressurized intake air to the high-pressure turbocharger, a turbogenerator for recovering heat energy from the exhaust gas downstream of the low-pressure turbocharger to generate electricity, and an exhaust gas recirculation (EGR) system comprising an EGR-pump drawing exhaust gas from an EGR inlet located between the low-pressure and high-pressure turbocharger turbines, wherein the EGR-pump controllably delivers exhaust gas to an EGR mixer in the pressurized intake air stream at a location between the low-pressure and high-pressure turbocharger compressors. An electronic control unit (ECU) is adapted to command the EGR-pump to deliver a desired EGR flow-rate to the engine block based on look-up tables and either open-loop and/or closed-loop control algorithms.

Abstract: A method of controlling exhaust gas recirculation (EGR) in a turbocharged engine system including multiple EGR paths to account for at least one of system constraints, or dead time and/or lag time associated with at least one of the EGR paths.

Abstract: A circuit for cooling exhaust gas being recirculated through an EGR system (36) of an engine (10) from an exhaust system (20) successively through first and second heat exchangers (38, 40) to an intake system (16) for entrainment with intake air. Each heat exchanger has a respective coolant inlet through which liquid coolant enters and a respective coolant outlet through which liquid coolant exits after having absorbed heat from recirculated exhaust gas. The circuit has a third heat exchanger (32) to which coolant coming from the outlet of one of the first and second heat exchangers rejects heat, and parallel branches (84, 86) through which coolant enters the inlet of the other of the first and second heat exchangers. One of the parallel branches has a fourth heat exchanger (34) to which coolant flowing through that branch rejects heat, and one or more devices (50, 50A) for controlling the quantity of coolant flowing through each branch.

Abstract: An exhaust gas treatment system includes a selective catalytic reduction (SCR) catalyst and a dosing control responsive to exhaust gas operating conditions for controlling the dosing rate of a reductant such as aqueous urea into the exhaust stream. When the dosing control determines that NH3 slip cannot be maintained within acceptable limits, even after disabling dosing, the dosing control generates a control message destined for the engine control unit (ECU) requesting that the ECU decrease the exhaust gas recirculation (EGR) rate. The decrease in the EGR rate is effective to increase the engine-out NOx level, which increases NOx availability in the SCR catalyst. As a result, excess NH3 in the SCR catalyst is used for NOx conversion rather than escaping out through the tailpipe as excessive NH3 slip.

Abstract: A method is disclosed for adjusting a target EGR mass flow in response to a current charge flow and target EGR fraction. The method includes interpreting an air-fuel ratio and a target air-fuel ratio. The method further includes interpreting a charge flow and a target EGR fraction. The method further includes determining an adjusted target EGR mass flow based on the air-fuel ratio, the target air-fuel ratio, the charge flow, and the target EGR fraction. The method further includes controlling an actuator based on the adjusted target EGR mass flow.

Abstract: A spark ignited gaseous fuel engine including an exhaust gas recirculation system and method for operating a gaseous fuel engine are provided. The exhaust gas recirculation system has an adjustable flow and is operable to supply exhaust gas to at least one engine cylinder. The engine further includes means for determining a value indicative of a charge density of a combustion mixture that includes gaseous fuel, air and exhaust gas supplied to the at least one cylinder, and adjusting a flow quantity through the exhaust gas recirculation system based at least in part on the value. The charge density may permit the controller to set a NOx output rate from the engine via a pre-determined correlation between charge density and NOx output.

Abstract: The present invention relates to an internal combustion engine comprising: a plurality of combustion chambers (41,42,43,44); an air induction system (45,45A,45B,46,47) for delivering air to each combustion chamber (41,42,43,44); a fuel system for delivering fuel to each combustion chamber (41,42,43,44); an exhaust system (48,50) for relaying combusted gases from the combustion chambers (41,42,43,44) to atmosphere; and an exhaust recirculation system (49,51) to relay combusted gases from the exhaust system (48,50) to at least one of the combustion chambers (42,43). The engine has a chamber deactivation operating mode in which at least one combustion chamber (41,44) is active and receives fuel and air which are combusted therein and at least one other combustion chamber (42,43) is deactivated and is supplied with no fuel by the fuel system. In the chamber deactivation operating mode the exhaust gas recirculation system (49,51) supplies combusted gas to the (or each) deactivated combustion chamber (42,43).

Abstract: A turbocharger for an internal combustion engine includes a turbine comprising a turbine wheel attached to a turbine shaft, the turbine wheel and shaft rotatably disposed in a turbine housing, the turbine housing comprising a turbine volute conduit, the turbine volute conduit having a turbine volute inlet and an EGR conduit inlet, the EGR conduit inlet radially spaced from the turbine volute inlet along the turbine volute conduit and opening into an EGR conduit that is joined to the turbine volute conduit. The turbine volute inlet is configured for fluid communication of an exhaust gas received from an engine to the turbine wheel, the EGR conduit configured for fluid communication of the exhaust gas to an engine intake conduit. The turbocharger also includes a compressor comprising a compressor wheel attached to the turbine shaft, the compressor wheel and turbine shaft rotatably disposed in compressor housing.

Abstract: An engine control system for a vehicle comprises a pump control module and a heating request determination module. The pump control module disengages a switchable water pump from an engine upon startup of the engine. The heating request determination module generates a heat request signal that indicates whether heating of a passenger cabin of the vehicle has been requested based on ambient air temperature, humidity of ambient air, and a status of an air conditioner clutch. The pump control module selectively engages the switchable water pump after the heat request signal is generated.

Abstract: An EGR control method to prevent condensation within the EGR system uses a temperature sensor signal from an EGR cooler exhaust gas outlet to model or estimate exhaust manifold gas temperature upstream of the cooler. If the estimated exhaust manifold gas temperature falls below a predetermined level, the engine control system closes or partially closes the EGR control valve to stop EGR flow through the cooler and the EGR valve.

Abstract: This invention relates to a method for protecting an exhaust gas recirculation (EGR) valve from fouling due to hydrocarbon condensation at low EGR cooler outlet exhaust temperatures. In modern internal combustion engines exhaust gas recirculation (EGR) valves provide a means to recirculate exhaust gases into the intake air stream. The EGR valve regulates the flow of exhaust gas entering the stream. The EGR valve can experience fouling due to the condensation of hydrocarbons at low EGR cooler outlet exhaust temperatures. Typically, fouling occurs when the internal combustion engine is operating at relatively low temperatures, namely during low speed and/or low torque operations. The effects of fouling an EGR valve include higher emission levels, reduction in fuel economy, and rough idling.

Abstract: An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

Abstract: An intake manifold (16) of an internal combustion engine (10) is charged to superatmospheric pressure by operating a first compressor (44) to compress fresh air diluted by exhaust gas into the intake manifold while operating a second compressor (24C) to compress undiluted fresh air into the intake manifold through a device (40) that allows flow in a direction from the second compressor into the intake manifold but not in an opposite direction.

Abstract: A system and method for controlling an engine control an EGR cooler bypass valve to divert at least a portion of EGR flow around an EGR cooler when operating under cooler fouling/plugging conditions, such as during idle, off-idle, exhaust system warm up and DPF regeneration or other post injection operation with EGR gas temperature below a corresponding threshold or with EGR low-temperature coolant temperature below a corresponding threshold. The system and method reduce exhaust gases passing through the EGR cooler that contain a high concentration of unburned or partially unburned fuel when the temperature in the EGR system is lower than the fuel condensation temperature.

Abstract: A low pressure EGR regulating valve is driven by an electric actuator, and an output of the electric actuator is transmitted to an intake air throttle valve through a link device. An ECU executes a failure determination to determine presence of a failure in a case where a sensed opening degree, which is sensed with a low pressure EGR opening degree sensor, is other than an opening degree that corresponds to a maximum opening degree of the throttle valve limited by a mechanical stopper. The ECU executes the failure determination after the energization of the electric actuator is stopped in response to stopping of the engine.

Abstract: A system and method for controlling an internal combustion engine having an EGR valve determine a base valve position to deliver a target flow using a stored map and adjust the base position in response to differential pressure across an orifice in the EGR flow to move the valve to a position different from the base position to provide the target flow.

Abstract: A device for controlling the exhaust-gas turbocharging of an internal combustion engine having an exhaust-gas turbocharging device, has an estimated value unit for determining a mass flow through a turbine system, a regulating unit for determining a regulating exhaust-gas back pressure as a function of a nominal charge pressure and an actual charge pressure, and also a unit for generating at least one actuating signal for at least one actuator of the turbine system as a function of the regulating exhaust-gas back pressure and of the mass flow through the turbine system, wherein the estimated value unit has a turbine system model for determining an estimated overall efficiency of the turbine system and a model for determining an estimated overall efficiency of a compressor system having at least two compressors, and wherein the regulating unit is set up to determine the regulating exhaust-gas back pressure using the estimated overall efficiencies

Abstract: An EGR flow rate control apparatus of an internal combustion engine is provided that can correct with high accuracy an EGR gas flow rate measured by a gas flow rate measurement apparatus in an EGR passage and control with high accuracy a gas flow rate regulating valve to reduce discharge amounts of PM and NOx in exhaust gases. An EGR flow rate control apparatus 10 of an internal combustion engine includes EGR flow channels 16, 20 that communicate exhaust pipe 11 with intake pipe 7, gas flow rate regulating valve 17 installed in EGR flow channels 26, 20 that regulates an EGR gas flow rate, and gas flow rate measurement apparatus 18 that is installed on an intake pipe 7 side with respect to the flow rate regulating valve 17 of EGR flow channels 16 and 20 and that measures an EGR gas flow rate flowing through the EGR flow channels 16 and 20.

Abstract: An exhaust gas recirculation system including an exhaust gas passageway which routes a flow of exhaust gas from an exhaust gas source to an intake manifold; an exhaust gas passageway valve which controls flow to the intake manifold; a cooling system coupled with the exhaust gas passageway positioned at a location upstream of the exhaust gas source and downstream of the intake manifold and operable to transfer heat from the flow of exhaust gas to a coolant in flow communication with the cooling system; a bypass passageway coupled with the exhaust gas passageway and bypassing the cooling system; a bypass valve operable to control flow through the bypass passageway; at least one valve operation sensor; and a controller operable to control the bypass valve to direct the flow of exhaust gas to the bypass passageway during exhaust gas recirculation based on a signal from the valve operation sensor.

Abstract: A control apparatus of an EGR control valve has an EGR control valve has an exhaust gas recirculation passage to circulate exhaust gas of an combustion engine from an exhaust gas passage to an intake air passage. A measurement unit measures a flow rate of EGR gas flowing in the exhaust gas recirculation passage, and a controller receives an input from the measurement unit and closes the EGR control valve if the EGR-gas flow rate is smaller than a predetermined threshold value when the EGR gas is flowing from the exhaust side to the intake side of the internal combustion engine.

Abstract: A device for fresh-gas supply for a turbocharged, compression-ignition, reciprocating-piston internal-combustion engine is provided. The engine has fresh-gas supply pipe and exhaust gas manifold pipe, between which an EGR device is installed. A tubular inside space section of the fresh-gas supply pipe located downstream of a turbocharger has a compressed-air connection with a volume control device, and a butterfly valve for controlling throughflow. Operation of the butterfly valve is controlled by an electronic control unit of the engine which processes sensor signals. A control valve of the EGR device, which is electronically controlled and controls the exhaust gas throughflow volume, is connected to the electronic control unit for synchronized operation of the butterfly valve with the volume control device.

Abstract: A condensation control system for a vehicle comprises a short route (SR) target module, a long-route (LR) target module, and a humidity adjustment module. The SR target module controls a first opening target for opening of a first exhaust gas recirculation (EGR) valve and a first throttle valve based on a SR target and a SR adjustment. The LR target module controls a second opening target for opening of a second EGR valve and a second throttle valve based on a LR target and a LR adjustment. The humidity adjustment module adjusts the SR and LR adjustments based on a humidity adjustment when condensation is detected in a system that provides a gas to an engine for combustion and determines the humidity adjustment based on a difference between a humidity within the system and a predetermined humidity.

Abstract: A method for controlling EGR gas flow in an internal combustion engine during ongoing operation includes determining an engine operating point and a preferred EGR fraction for a cylinder charge based upon the engine operating point. A feed-forward command for controlling an external EGR gas flowrate to an engine intake manifold based upon the preferred EGR fraction for the cylinder charge is determined. An EGR ratio in the intake manifold is determined. And, the external EGR gas flowrate is controlled based upon the estimated EGR ratio in the intake manifold and the feed-forward command for controlling the external EGR gas flowrate.

Abstract: A power plant includes an engine configured to receive charge air and produce exhaust. A first turbo machine is configured to be driven by the exhaust and drive a compressor that receives air. The compressor is configured to produce the charge air. A second turbo machine is configured to receive a portion of the exhaust and rotationally drive a pump in response thereto. High temperature and low temperature EGR heat exchangers are arranged in the exhaust gas recirculation passage serially relative to one another upstream from the pump. A heat exchanger arranged in the exhaust gas recirculation passage upstream from the pump. A water separator is arranged in the exhaust gas recirculation passage fluidly between the heat exchanger and the pump. An EGR catalyst is arranged in the exhaust gas recirculation passage upstream from the heat exchanger.

Abstract: An exhaust recirculation apparatus is provided to an engine. A high-pressure EGR passage branches from upstream of a turbine of a turbocharger in an exhaust system for recirculating exhaust gas to downstream of a compressor of the turbocharger in an intake system. A high-pressure EGR regulating unit controls exhaust gas through the high-pressure EGR passage. A low-pressure EGR passage branches from downstream of the turbine in the exhaust system for recirculating exhaust gas to upstream of the compressor in the intake system. A low-pressure EGR regulating unit controls exhaust gas through the low-pressure EGR passage. A control unit feedback-controls the high-pressure EGR regulating unit, and open-controls the low-pressure EGR regulating unit when exhaust gas is recirculated through the high-pressure EGR passage and the low-pressure EGR passage. The control unit feedback-controls the low-pressure EGR regulating unit when exhaust gas is recirculated through only the low-pressure EGR passage.

Abstract: If a demanded power exceeds a predetermined threshold, where the threshold is based on a catalyst temperature, power from a power storage unit is supplied to a wheel.

Abstract: An EGR control unit for enhancing the performance as to the EGR rate and the engine acceleration, the unit being configured so as to control the EGR valve and the intake air valve with a simple control command signal that makes both the valves be operated in a coupled mode, whereby the response performance as to the engine speed during acceleration as well as the EGR gas flow rate is enhanced by means of compensation regarding the dead zones inherent in the intake air throttle valve and the EGR valve.

Abstract: The present invention is a dual-stage fuel injection strategy for compression ignition engines in which 15-40% of the fuel is injected into the combustion chamber no later than about ?20 to ?30 CA ATDC and as early as IVC. The remaining fuel is then injected in one or more fuel pulses, none of which start before about ?20 to ?30 CA ATDC. The fuel injected early in the compression stroke forms a lean mixture that burns with low soot and low NOx emissions. The combustion of that fuel serves to increase in-cylinder temperature such that the ignition delay of subsequent fuel injection pulses is short. This mode is utilized when it is predicted that a NOx spike is imminent. Various other alternative methods for reducing NOx spikes are also disclosed such as specialized EGR systems that can provide EGR with low manifold vacuum.