Abstract: A method for diagnosing a sensor unit of an internal combustion engine, in which an output signal of the sensor unit is compared to a setpoint value which is specified independently from the output signal. The setpoint value relates to a periodic characteristic, and the variation over time of the value of the output signal of the sensor unit or a variable which is derived from the value variation over time is analyzed with regard to this periodic characteristic.

Abstract: In a non-critical pressure region where a pressure ratio [Pm/Pthrup(i?1)] of an intake air pressure Pm (throttle downstream pressure) detected by an intake air pressure sensor to a previous throttle upstream pressure Pthrup(i?1) is greater than a predetermined value B, the previous throttle upstream pressure Pthrup(i?1) is substituted for one of two terms of the throttle upstream pressures Pthrup(i) included in an intake system model so that present throttle upstream pressure Pthrup(i) is calculated. In a critical pressure region where the pressure ratio is less than or equal to the predetermined value B, a physical value f(Pm/Pthrup(i)) using a pressure ratio [Pm/Pthrup(i)] of the intake air pressure Pm to a present throttle upstream pressure Pthrup(i) as a parameter is regarded as a steady value fc so that the present throttle upstream pressure Pthrup(i) is calculated.

Abstract: A method for providing a characteristic quantity for a state of an air system of a supercharged internal combustion engine includes: detecting a characteristic quantity measured value as characteristic quantity information with the aid of a sensor; providing a characteristic quantity model, using which a characteristic quantity model value is computed on the basis of one or more quantities different from the characteristic quantity measured value; and providing the characteristic quantity either based on the characteristic quantity measured value or on the characteristic quantity model value computed by the characteristic quantity model, as a function of a state of the air system.

Abstract: An arrangement of a mass intake air flow measurement device suitable for integrating a humidity sensing device as well as a temperature sensing device and a pressure sensing device is provided. A second bypass passage 501 bypassing a bypass passage 205 is formed and a humidity sensing device 500 is mounted in the second bypass passage 501. A second bypass passage inlet 502 and a second bypass passage outlet 503 formed in a wall surface of the bypass passage 205 are opened parallel to the direction of flow of air flowing in the bypass passage 205.

Abstract: A computer calculates an estimated cylinder-intake-air amount based on outputs from an airflow meter and a throttle position sensor, and then calculates a reference cylinder-intake-air amount based on an air-fuel ratio in an exhaust gas and fuel injection amount. An error of the estimated cylinder-intake-air amount is calculated by comparing the reference cylinder-intake-air amount with an estimated cylinder-intake-air amount base value. The error is low-pass filtered. The estimated cylinder-intake-air amount base value is corrected to obtain the final estimated cylinder-intake-air amount.

Abstract: An intake pressure sensor is provided in an intake manifold of a first cylinder. During steady operation, intake quantities of respective cylinders are sensed with an airflow meter provided in an intake pipe of an engine, and the intake quantity of the first cylinder is compared with the intake quantities of the other cylinders to obtain intake pressure variation correction coefficients of the other cylinders. Also, average intake pressure of the first cylinder is corrected with the intake pressure variation correction coefficients to calculate average intake pressures of the other cylinders. During transient operation, estimation intake pressure is anticipated from a target opening degree of an intake throttle valve with the use of a physics model. Intake quantities of the respective cylinders are calculated with the use of the estimation intake pressure and the intake pressure variation correction coefficients.

Abstract: A process is provided for monitoring the filter restriction level of a filter element. The filter element is utilized by an air induction system deployed on a vehicle that includes a mass air flow sensor, a manifold pressure sensor, and a throttle position sensor. The process includes receiving (i) throttle position from the throttle position sensor, (ii) mass flow rate from the mass air flow sensor, and (iii) manifold pressure from the manifold pressure sensor. A reference pressure is determined from the received mass flow rate and the received throttle position, a pressure differential is established between the reference pressure and the received manifold pressure, and a filter restriction level is identified from the established pressure differential and the received mass flow rate.

Abstract: A method of estimating an air charge in at least one combustion cylinder of an internal combustion engine includes calculating cylinder mass air flow based upon a modified volumetric efficiency parameter; and calculating the intake throttle mass air flow based upon a throttle air flow discharge parameter and a fuel enrichment factor. Three models including a mean-value cylinder flow model, a manifold dynamics model, and a throttle flow model are provided to estimate the air charge in the at least one combustion cylinder and to control delivery of fuel to the fuel delivery system.

Abstract: The present invention provides an air flow measuring device comprising a housing with a sub-passage having a inlet and a outlet for air flow formed in the housing, the sub-passage further having a predefined curvature with a maximum downstream point and a flow measuring element located in the sub-passage at a position at least further downstream from the point.

Abstract: A device for intake manifold pressure-based determination of the air mass flowing into the cylinder combustion chamber is provided. A logic unit determines the inflowing air mass based on the intake manifold pressure using a calculation model for load detection that determines the intake manifold pressure in an upper partial range of the intake manifold pressure. A sensor device for direct detection of the intake manifold pressure measures the intake manifold pressure only in a lower partial range of the intake manifold pressure in the internal combustion engine. The logic unit determines the inflowing air mass as a function of the intake manifold pressure measured by the sensor deice when within the lower partial range of the intake manifold pressure, and based on the intake manifold pressure determined by use of the calculation model when within the upper partial range.

Abstract: A process for the evaluation of the true fuel flow rate supplied to a tested vehicle engine, in particular an industrial vehicle, the process including: the determination of a reference fuel flow rate, corresponding to the exact flow rate measured on a reference engine of the same type as the tested engine under various operation conditions as a function of a load the engine is subjected to; the measurement of the deceleration (?n/?t) of the tested engine from a first to a second rotation speed which are preset in the absence of fuel supply, corresponding to a load the engine is subjected to; the determination, based on said deceleration, and based on the actual operation conditions of the engine under similar load conditions, of the corresponding reference flow rate.

Abstract: An internal combustion engine has a cylinder with a combustion chamber delimited by a reciprocating piston that drives a crankshaft rotatably supported in a crankcase. The internal combustion engine has an intake passage, an exhaust connected to the combustion chamber, a device supplying fuel, and a control device controlling at least one operating parameter of the internal combustion engine. The internal combustion engine is operated in that a pressure is measured in operation of the internal combustion engine, an adjustable value for at least one operating parameter of the internal combustion engine is deteremined based on the measured pressure, and the determined adjustable value is set for optimized running of the engine.

Abstract: A method for setting a mass flow rate of air to be provided in a charging mode; in the charging mode (where a throttle valve is open), the pressure prevailing in an induction pipe only being set via an adjustable mass flow rate of supplied air; a requested torque corresponding to a mass flow rate of air into a cylinder, the mass flow rate of air into the cylinder being adjustable via the pressure in the induction pipe; to set the mass flow rate of air into the cylinder, the pressure in the induction pipe being adjusted by a control system in accordance with a specifiable dynamic charge response characteristic.

Abstract: A control apparatus for an internal combustion engine provided with a fuel supply mechanism capable of adjusting a fuel supply amount includes a flow rate sensor that detects an intake air flow rate that represents a flow rate of air admitted into a combustion chamber of the internal combustion engine, a pressure sensor that detects a pressure of the air admitted into the combustion chamber of the internal combustion engine, a characteristic change estimation unit that estimates a characteristic change of the internal combustion engine in accordance with the intake air flow rate detected by the flow rate sensor and the intake air pressure detected by the pressure sensor, and a fuel supply mechanism control unit that controls the fuel supply mechanism. The fuel supply mechanism control unit controls the fuel supply mechanism such that the characteristic change in the internal combustion engine is compensated in accordance with an estimation performed by the characteristic change estimation unit.

Abstract: In an exhaust-gas turbocharger for an internal combustion engine comprising an exhaust-gas turbine arranged in an exhaust strand of the internal combustion engine and a compressor arranged in an intake tract and connected to the exhaust gas turbine so as to be driven thereby, the compressor including a compressor wheel and a compressor housing surrounding the compressor wheel and having an inlet duct, a dynamic pressure probe is provided upstream of the compressor wheel in the inlet duct for measuring at least the total pressure in the air flow into the compressor.

Abstract: In an intake air mass flow measurement device, for preventing clogging in a pressure intake tube due to water or the like entering the pressure intake tube in a device measuring a pressure in the intake air tube, the intake air mass flow measurement device includes a mass air flow measurement device for measuring an intake air mass flow in an intake air tube; and a pressure sensing device for sensing pressure in the intake air tube, the pressure sensing device being integrated with the mass air flow measurement device, and an aperture plane opened to the inside of a main air flow passage for detection of the pressure takes in pressure by using a gap generated between a main air flow passage constituting member and an insertion part of the mass air flow measurement device when a measurement part of the mass air flow measurement device is inserted into the main air flow passage. With this construction, it is possible to provide a structure in which water or the like can hardly clog the pressure intake port.

Abstract: A method for setting a mass flow rate of air to be provided in a charging mode; in the charging mode (where a throttle valve is open), the pressure prevailing in an induction pipe only being set via an adjustable mass flow rate of supplied air; a requested torque corresponding to a mass flow rate of air into a cylinder, the mass flow rate of air into the cylinder being adjustable via the pressure in the induction pipe; to set the mass flow rate of air into the cylinder, the pressure in the induction pipe being adjusted by a control system in accordance with a specifiable dynamic charge response characteristic.