Abstract: A method is provided for estimating the relative humidity in an intake line of an internal combustion engine provided with an intake manifold connected to the intake line, an exhaust line, and a Low Pressure EGR (LPE) conduit which fluidly connects the exhaust line to a connecting point of said intake line. The method includes, but is not limited to calculating specific humidity in the exhaust line, as a function of the O2 concentration in said exhaust line; determining ambient specific humidity; calculating specific humidity in a portion of the intake line comprised between said connecting point and said intake manifold, as a function of a flow of external air entering into said intake line, a flow of exhaust gases coming from said Low Pressure EGR (LPE) conduit, the specific humidity in said exhaust line and the ambient specific humidity; calculating the relative humidity in said portion of the intake line, as a function of the specific humidity thereof.

Abstract: A system for controlling a continuous variable valve lift actuator of a diesel engine and a method thereof stabilize exhaust gas and improve performance by variably controlling lift and timing of intake and exhaust valves based on combustion state and driving purpose. The method may include, recognizing a driving purpose and combustion state by detecting driving conditions, temperature of exhaust gas at predetermined locations on an exhaust pipe, and NOx concentration contained in the exhaust gas, determining target position and timing of intake and exhaust valves by applying the driving purpose and the combustion state to a predetermined map table, controlling position and timing of the intake and exhaust valves by actuating a CVVA, detecting combustion pressure in a combustion chamber, and modifying fuel injection amount according to the combustion pressure.

Abstract: An electrochemical gas sensor is provided for a motor vehicle. The gas sensor contains a digital controller and a detection circuit. The digital controller captures, by a feedback input, a value of the voltage applied to the inside of the gas sensor cell. The output of the digital controller provides a control value for the current flowing in the gas sensor cell. The detection circuit is used to detect the properties of the gas sensor cell and to adjust the dynamic control properties of the digital controller corresponding to the properties of the gas sensor cell.

Abstract: An exhaust gas recirculation assembly for an engine is disclosed in which an EGR cooler and a bypass passage are combined in a single housing. Two EGR valves are used to control exhaust gas flow through the EGR cooler and the bypass passage respectively. By using two EGR valves, the disclosure obviates bypass baffles or flaps which can suffer from leakage problems. The arrangement of the EGR valves permits the use of un-cooled EGR valves and the EGR valves can be used to control not only the flow of exhaust gas through the EGR cooler or bypass passage, but also the EGR flow for the engine.

Abstract: An engine control system includes a unit which outputs a command for changing an air-fuel ratio of an exhaust gas, a unit which computes an in-cylinder oxygen concentration, a memory which stores a first value and a second value of parameters (ignition timing, injection pressure, pilot injection quantity). The first value is set in a case that the in-cylinder oxygen concentration is a first oxygen concentration. The second value is set in a case that the in-cylinder oxygen concentration is a second oxygen concentration which is higher than the first oxygen concentration. The values of the parameters are set in such a manner as to correlate to the in-cylinder oxygen concentration of during a transition period of the air-fuel ratio. The values of the parameters are obtained by an interpolation based on the first and the second value of the parameter and the in-cylinder oxygen concentration.

Abstract: A diesel engine system includes a cylinder, an exhaust manifold, an exhaust gas recirculation (EGR) manifold, and a valve. The exhaust manifold is fluidly coupled with the cylinder and directs exhaust generated in the cylinder to an exhaust outlet that delivers the exhaust to an external atmosphere. The EGR manifold is fluidly coupled with the cylinder and recirculates the exhaust generated in the cylinder back to the cylinder as at least part of intake air that is received by the cylinder. The valve is disposed between the cylinder and the exhaust manifold and between the cylinder and the EGR manifold. The valve has a donating mode and a non-donating mode. The valve fluidly couples the cylinder with the EGR manifold when the valve is in the donating mode and fluidly couples the cylinder with the exhaust manifold when the valve is in the non-donating mode.

Abstract: The present invention relates to a method for reintroducing exhaust gas to the intake of an internal-combustion engine wherein, during the engine exhaust phase, part of the exhaust qas contained in combustion chamber (60) of cylinder (10) of the engine is fed, for an operating range of this engine, into a first fluid circulation circuit (C1) and the other part of said gas is discharged into an exhaust circuit. According to the invention, the method consists: during the engine intake phase, in cooling the exhaust qas fed into fluid circulation circuit (C1), in mixing the cooled recirculated exhaust qas with fresh supply air (AF) coming from engine supply circuit (44), in feeding the mixture of recirculated exhaust gas and of supply air into a second fluid circulation circuit (C2), and in cooling said mixture fed into second circuit (C2) prior to feeding it into combustion chamber (60).

Abstract: A method comprising operating a compressor; obtaining operating parameters of the compressor; starting a counter for a crankshaft angle from 0 to 360 degrees; calculating piston displacement and a volume of gas in a cylinder of the compressor as a function of the angle; and calculating a pressure within the cylinder.

Abstract: A valve train of an internal combustion engine having a swing of a link mechanism that is stabilized to stabilize the operating characteristics of an engine valve. A camshaft is provided together with a valve operating cam pivotally supported by the camshaft so as to operatively open and close an engine valve. A link mechanism allows a drive cam rotated integrally with the camshaft to swing the valve operating cam, and a drive mechanism swings the link mechanism, wherein opening and closing of the engine valve are started in a buffer section of the valve operating cam, and opening/closing timing of the engine valve is controlled by the drive mechanism swinging the valve operating cam via the link mechanism, without the provision of a buffer transition section and a buffer constant-speed section encountered at the time of transiting from a base circle to a cam lobe of the drive cam.

Abstract: A control system for a hybrid vehicle that includes an internal combustion engine and an electric motor includes an engine speed control module, an air pressure control module, and an engine torque control module. The engine speed control module increases engine speed during a first calibration period based on a driver torque request and a predetermined torque threshold. The air pressure control module decreases intake manifold pressure (MAP) of the engine during a second calibration period based on the driver torque request and the predetermined torque threshold. The engine torque control module starts the engine during a period after the first and second calibration periods by activating N of M cylinders of the engine, wherein N is based on the driver torque request and the predetermined torque threshold.

Abstract: An internal combustion engine includes a muffler configured to reduce exhaust gas noise, a choke valve configured to control a flow of air in a carburetor, a thermally responsive element coupled with the choke valve and configured to move the choke valve in response to a temperature change in the thermally responsive element, and a thermally conductive member. The muffler has a housing defining an interior and an exterior. The thermally conductive member has a first portion positioned in the interior of the muffler in direct contact with the exhaust gases and extends through the muffler housing to the exterior of the muffler. The thermally conductive member also has a second portion positioned exteriorly of the muffler and coupled to the thermally responsive element, the thermally conductive member configured to conduct heat from exhaust gases within the muffler to the thermally responsive element.

Abstract: A method of controlling exhaust gas flow in an internal combustion engine system, and products and systems using same.

Abstract: A method for controlling combustion in a direct injection internal combustion engine operable in a lean combustion mode includes monitoring in-cylinder pressure, utilizing a time-based filter to calculate an actual combustion noise based upon the monitored in-cylinder pressure, monitoring combustion control parameters utilized by the engine, determining an expected combustion noise based upon the monitored combustion control parameters, comparing the actual combustion noise to the expected combustion noise, and adjusting the combustion control parameters based upon the comparing.

Abstract: A control system includes a speed determination module and a profile estimation module. The speed determination module determines previous engine speeds based on a predetermined profile of a crankshaft position sensor and previous pulse times corresponding to teeth on the crankshaft position sensor. The profile estimation module performs data fitting to determine an estimated profile of the crankshaft position sensor based on the previous pulse times and the previous engine speeds. The speed determination module determines present engine speeds based on the estimated profile and present pulse times corresponding to the teeth on the crankshaft position sensor.

Abstract: An outboard motor includes an engine including a vertically extending crankshaft, a rope reel, a transmitting member, a force accumulation spiral spring, and an engine cover arranged to cover these components. The rope reel includes a plate portion arranged to be rotatable about the rotational center axis of the crankshaft and a rope winding portion provided integrally with the plate portion at the peripheral edge thereof and arranged to be wound with a rope to start the engine. The transmitting member is arranged to be rotatable about the rotational center axis of the crankshaft and to transmit rotation to the crankshaft. The force accumulation spiral spring is disposed on the opposite side of the engine with respect to the plate portion of the rope reel. The force accumulation spiral spring is arranged to accumulate a torque applied to the rope reel and transmit the torque to the transmitting member, first and second ends of the spring being fixed, respectively, to the rope reel and the transmitting member.

Abstract: An internal combustion engine can be operated by a fuel mixture consisting of a base fuel and an alternative fuel. Concentration values (ETH_PERC) of the alternative fuel are determined in at least two different ways for operating the internal combustion engine. A reliable concentration value of the alternative fuel is determined depending on the various determined concentration values (ETH_PERC).

Abstract: A method and a control system are provided for estimating oxygen concentration downstream a diesel oxidation catalyst within a diesel engine system. The method includes, but is not limited to at least an intake manifold, a combustion chamber, an exhaust manifold, and the diesel oxidation catalyst located in the exhaust line upstream a diesel particulate filter, the method comprising: determining unburned fuel mass flow ejected from the combustion chamber, determining air mass fraction in the exhaust manifold, estimating air mass fraction downstream the diesel oxidation catalyst as a function of said unburned fuel mass flow and said air mass fraction in the exhaust manifold, estimating oxygen concentration downstream the diesel oxidation catalyst as a function of the estimated air mass fraction downstream the diesel oxidation catalyst.

Abstract: A method and control module includes a manifold absolute pressure comparison module that determines a function of the manifold absolute pressure and an average manifold absolute pressure for a plurality of cylinders and that compares the manifold absolute pressure parameter to a manifold absolute pressure threshold. The control module includes a misfire event module that compares the misfire parameter to a misfire threshold. A hardware remedy module performs a valve actuation hardware remedy in response to comparing the manifold absolute pressure and comparing the misfire parameter.

Abstract: Methods and systems are provided for improving fuel usage while addressing knock by adjusting the use of spark retard and direct injection of a fluid based on engine operating conditions and the composition of the injected fluid. One or more engine parameters, such as EGR, VCT, boost, throttle position, are coordinated with the direct injection to reduce torque and EGR transients.

Abstract: In an internal combustion engine, on a cylinder head side, a tumble flow is formed that is directed from an intake vent opened on the cylinder head to an exhaust vent opened on the cylinder head. A direct injection valve injects fuel directly into a combustion space. The direct injection valve injects the fuel toward a section where a piston top surface intersects with a cylinder inner surface, at a point closer to an intake top dead center than a middle between the intake top dead center and an intake bottom dead center, and thereafter injects the fuel into the combustion space again.