Abstract: Methods and systems are provided for estimating an exhaust air/fuel ratio based on outputs from an exhaust oxygen sensor. In one example, a method may include adjusting engine operation based on an air-fuel ratio estimated based on an output of the exhaust oxygen sensor and a learned correction factor. For example, the oxygen sensor may operate in a variable voltage mode in which a reference voltage of the oxygen sensor may be adjusted between a lower first voltage and a higher second voltage, and the learned correction factor is based on the second voltage.

Abstract: Methods and systems for operating an engine during conditions where ambient humidity changes over time are presented. In one non-limiting example, an engine airflow is adjusted to increase engine airflow during high humidity conditions such that an engine may provide equivalent torque output during the high humidity conditions as compared to when the engine is operated during low humidity conditions.

Abstract: An exhaust gas condensate control method includes selecting modeling objects from the exhaust gas recirculation (EGR) system, acquiring control factors from the modeling objects, such as mass, temperature, pressure, absolute humidity, relative humidity, partial water vapor pressure of the exhaust gas and a gas mixture, calculating an estimated relative humidity value, a desired relative humidity value from estimated relative humidity value, and an allowable relative humidity limit and a current relative humidity value of the EGR system, and precluding production of condensate in the EGR system by feedback-controlling the intake air flow rate of a mixing pipe line, the opening amount of an LP-EGR (low pressure) valve, and boost pressure by using an applied control value compensating the desired relative humidity value. An EGR system may be an LP-EGR type or an HP-EGR (high pressure)+LP-EGR type.

Abstract: Methods systems and device for detecting humidity in air through use of an ammonia sensor included in the exhaust of an engine, such as a diesel engine are provided. In one example, a method for an engine having an exhaust with an ammonia sensor includes adjusting an operating parameter in response to ambient humidity, the ambient humidity based on a first ammonia sensor reading at a first exhaust air-fuel-ratio and a second ammonia sensor reading at a second exhaust air-fuel-ratio.

Abstract: Methods and systems are provided for improving a balance between engine fuel economy and exhaust emissions in an off-highway vehicle. One example method includes adjusting an engine injection timing based on an ambient NOx level estimated by a NOx sensor in the engine intake. Another example method includes adjusting a trip plan with a time in notch duty cycle based on a deviation from the time in notch duty cycle from a reference duty cycle.

Abstract: Methods systems and device for detecting humidity in air through use of an ammonia sensor included in the exhaust of an engine, such as a diesel engine are provided. In one example, a method for an engine having an exhaust with an ammonia sensor includes adjusting an operating parameter in response to ambient humidity, the ambient humidity based on a first ammonia sensor reading at a first exhaust air-fuel-ratio and a second ammonia sensor reading at a second exhaust air-fuel-ratio.

Abstract: A diagnostic system for a vehicle comprises a humidity module and a fault diagnostic module. The humidity module outputs a first humidity value based on a humidity measurement of a humidity sensor of the vehicle and outputs a second humidity value based on humidity data from a data source that is external to the vehicle. The fault diagnostic module selectively diagnoses a fault in the humidity sensor based on the first humidity value and the second humidity value.

Abstract: Various systems and methods are described for operating an engine in a vehicle in response to an ambient humidity generated from an exhaust gas sensor. One example method comprises, during engine non-fueling conditions, where at least one intake valve and at least one exhaust valve of the engine are operating, generating an ambient humidity from the exhaust gas sensor and, under selected engine combusting conditions, adjusting an engine operating parameter based on the ambient humidity.

Abstract: An exhaust gas recirculation (EGR) system for an engine and a method of operating that system is disclosed. The system has a conduit arrangement for conducting exhaust gas from an exhaust side of the engine to an intake side of the engine, a valve arrangement configured for controlling the amount of exhaust gas to be recirculated and a conduit arrangement for providing intake air to the intake side of the engine. A sensor arrangement is provided and is configured to sense at least one parameter indicative of the humidity of the recirculated exhaust gas and the intake air at the intake side of the engine. A control arrangement is configured to receive a signal from the first sensor arrangement and further is configured to control the valve arrangement in response to a determination by the control arrangement that the first parameter is outside a desired range for low-NOx emission during a subsequent combustion period.

Abstract: In turbocharged engines, there is the problem that, in particular under load, the ambient pressure (AMP) cannot be determined directly from the measurement values of a charge-pressure sensor (8). In order to avoid the installation of a further pressure sensor which is suitable for the detection of the ambient pressure (AMP), it is proposed that, during a negative load step of the internal combustion engine in which a switch takes place from supercharged engine operation into non-supercharged engine operation, the charge-pressure sensor (8) measures the transient profile of the charge pressure (PUT). A value for the ambient pressure (AMP) is determined from the transient profile of the charge pressure (PUT). Through the pressure value for the present ambient pressure (AMP), it is possible to optimize the engine operation for example when travelling up a slope.

Abstract: A method of controlling a motor vehicle is disclosed. The method can be used to determine an ambient pressure value without the use of an ambient pressure sensor. The ambient pressure value can be used for controlling a set of fuel injectors. The method can include provisions for adjusting the ambient pressure value to correct for errors introduced by engine wear and other factors.

Abstract: Various systems and methods are described for operating an engine in a vehicle in response to an ambient humidity generated from an exhaust gas sensor. One example method comprises, during engine non-fueling conditions, where at least one intake valve and at least one exhaust valve of the engine are operating, generating an ambient humidity from the exhaust gas sensor and, under selected engine combusting conditions, adjusting an engine operating parameter based on the ambient humidity.

Abstract: An engine controller performs low opening degree control during a first intake stroke period since an engine start is commenced until first intake strokes of respective cylinders end. Thus, an opening degree of an intake throttle valve is controlled to a fully closed position or proximity of the fully closed position such that intake pressure downstream of the intake throttle valve becomes equal to or lower than critical pressure with respect to intake pressure upstream of the intake throttle valve during an intake stroke of each cylinder. The controller calculates a leak air quantity at the time when the intake throttle valve is fully closed based on an intake air quantity sensed during the low opening degree control. The controller corrects a feedback gain of idle speed control in accordance with the leak air quantity of the intake throttle valve.

Abstract: A humidity based control system for an internal combustion engine includes a calculation module and a calibration module. The calculation module determines a humidity of air used in a combustion process of the internal combustion engine. The control module selectively controls spark timing and exhaust dilution in the internal combustion engine based on the humidity.

Abstract: An engine air supply control method relating to a turbocharged engine including an intake manifold (20) which is disposed downstream of the compressor of the turbocharger (14) and an exhaust manifold (22) which is disposed upstream of the turbine of the turbocharger (14). The method includes determining the mass air flow supplying the engine and/or the pressure in the intake manifold (20) and the temperature in the exhaust manifold. The pressure in the exhaust manifold (22) is determined as a function of the pressure in the intake manifold (20), the engine speed, the temperatures in the cylinders (4) and in the exhaust manifold (22), the pressure in the intake manifold (20) being optionally determined from the mass air flow. Inversely, the pressure in the intake manifold.

Abstract: A system and method for utilizing a humidity sensor with an internal combustion engine of a vehicle is described. Specifically, information from the humidity sensor is used to adjust a desired air-fuel ratio to reduce engine misfire while improving vehicle fuel economy. Further, such information is also used to adjust timing and/or lift of the valve in the engine cylinder. Finally, diagnostic routines are also described.

Abstract: A system and method for controlling operation of a gasoline internal combustion engine capable of running in a spark ignition mode and a homogeneous charge compression ignition mode. The method and system implementation include determining humidity of air to be drawn into a combustion cylinder of the engine, and controlling an operating parameter of the engine that affects the homogeneous charge compression ignition mode of operation.

Abstract: A control system for estimating the performance of a compressor is disclosed. The control system has a compressor fluidly connected to an inlet manifold of a power source. The control system also has a power source speed sensor to provide an indication of a rotational speed of the power source, an inlet pressure sensor to provide an indication of a pressure of a fluid within the inlet manifold, an inlet temperature sensor to provide an indication of a temperature of the fluid within the inlet manifold, an atmospheric pressure sensor to provide an indication of an atmospheric pressure, and a control module in communication with each of the sensors. The control module is configured to monitor an engine valve opening duration and an exhaust gas recirculation valve position, and estimate a compressor inlet pressure based on the provided indications, the monitored duration, and the monitored position.

Abstract: A system and method for utilizing a humidity sensor with an internal combustion engine of a vehicle is described. Specifically, information from the humidity sensor is used to adjust a desired air-fuel ratio to reduce engine misfire while improving vehicle fuel economy. Further, such information is also used to adjust timing and/or lift of the valve in the engine cylinder. Finally, diagnostic routines are also described.

Abstract: A system and method for utilizing a humidity sensor with an internal combustion engine of a vehicle is described. Specifically, information from the humidity sensor is used to adjust a desired air-fuel ratio to reduce engine misfire while improving vehicle fuel economy. Further, such information is also used to adjust timing and/or lift of the valve in the engine cylinder. Finally, diagnostic routines are also described.

Abstract: The invention relates to a fuel metering device comprising a fuel chamber, a fuel inlet which can be opened and closed and leads to the fuel chamber, and at least one fuel outlet leading from the fuel chamber to a suction channel of an internal combustion engine. Part of a wall of the fuel chamber consists of a first element which can be moved according to a pressure difference between a pressure in the fuel chamber and an ambient air pressure, the element being coupled to a closing element for opening and closing the fuel inlet. The said fuel metering device enables a quantity of fuel, which is supplied to the suction channel for a pre-defined operating position of the internal combustion engine, to be automatically regulated according to the ambient air pressure.

Abstract: A multicylinder homogeneous charge compression ignition (HCCI) engine with a control system designed to maintain stable HCCI combustion during engine speed/load transitions by: (1) determining “combustion parameter” values such as the maximum rate of pressure rise for each cycle of each cylinder, (2) adjusting engine operating parameters (such as charge-air intake temperature, intake pressure (boost), or charge-air oxygen concentration) to effect a change in the combustion parameter value, (3) thereafter adjusting an engine “control parameter” (e.g., commanded fuel quantity) to each cylinder to maintain a desired target for the combustion parameter value, and (4) individually adjusting cooling, heating and/or fuel command to deviating cylinders to achieve uniform combustion. Additional strategies such as averaging of combustion parameter values and use of deadband regions in the control of HCCI combustion are also set forth.

Abstract: A valve train system for operating an intake valve of an internal combustion engine, in which an operation amount of the intake valve is controlled. When it is determined that there is a need of improving a fuel efficiency by increasing the compression ratio within the combustion chamber on the basis of an engine operating state, an exhaust valve is opened and subsequently closed after an intake stroke until the pressure within the exhaust chamber becomes equal to the pressure within the exhaust passage so as to increase the compression ratio within the exhaust valve.

Abstract: A system for diagnosing operation of a cooling system for an internal combustion engine includes a coolant temperature sensor producing a temperature signal corresponding to coolant fluid temperature, means for determining either an engine load or a throttle percentage, and a control computer configured to diagnose operation of the cooling system as a function of the temperature signal, either the engine load or throttle percentage, and a fuel delivery command for controllably supplying fuel to the engine. After expiration of a diagnostic period, the control computer diagnoses the cooling system as normally operating if the diagnostic period ended by the temperature signal meeting or exceeding a predefined temperature and if a total energy used by the engine during the diagnostic period is less than an estimated energy, and diagnoses the cooling system as failing if the total energy used during the diagnostic period otherwise meets or exceeds the estimated energy.

Abstract: A system and method for utilizing a humidity sensor with an internal combustion engine of a vehicle is described. Specifically, information from the humidity sensor is used to adjust a desired air-fuel ratio to reduce engine misfire while improving vehicle fuel economy. Further, such information is also used to adjust timing and/or lift of the valve in the engine cylinder. Finally, diagnostic routines are also described.

Abstract: A method for controlling condensation in an engine. A set of signals indicative of an intake manifold temperature, intake manifold pressure, intake air temperature, intake air humidity, engine speed, and exhaust gas mask flow rate is provided. A critical value that indicates that condensation could occur is calculated. The critical value is compared to a predetermined threshold value or range. An exhaust gas recirculation valve is closed if the critical value exceeds the predetermined threshold value or range. The exhaust gas recirculation valve is opened if the predetermined threshold value or range is not exceeded.

Abstract: A device for estimating the amount of intake air of an internal combustion engine comprising intake pipe pressure calculation means for calculating an intake pipe pressure, at this time, downstream of the throttle valve, and intake air amount calculation means for calculating the amount of intake air, at this time, based on the intake pipe pressure at this time calculated by said intake pipe pressure calculation means, is provided. The intake pipe pressure calculation means calculates the intake pipe pressure at this time by using the intake pipe pressure calculated at the last time and the amount of air passing through the throttle valve at the last time calculated by means for calculating the amount of air passing through the throttle valve.

Abstract: A fuel vapor treatment system is provided that diagnoses failure of the purge valve using one absolute pressure sensor. The fuel vapor treatment system includes a fuel tank, a canister, a drain cut valve, a purge valve, purge piping and a sensor. The canister adsorbs fuel vapor evaporated from the fuel tank. The drain cut valve controls the introduction of air into the canister. The purge valve is disposed between the canister and an intake passage into which fuel vapor flows from the canister. The purge piping communicates between the fuel tank and the intake passage via the canister. The sensor detects the absolute pressure inside the purge piping. The fuel vapor treatment system is further equipped with an atmospheric pressure setting device that sets the value detected by the sensor when the drain cut valve is open as the atmospheric pressure used for controlling the engine.

Abstract: A system and method to predict engine air amount for an internal combustion engine is described. Included is a method to predict a change in engine air amount based on engine position. This method especially suited to engine starts, where engine air amount is difficult to predict due to low engine speed and limited sensor information. The system and method provides the prediction of engine air amount without extensive models or calibration. Fuel is supplied based on the predicted engine air amount.

Abstract: A process for providing a real-time estimation of in-cylinder NOx production rates during a combustion process in an internal combustion engine. The process employs a model that takes into account fundamental in-cylinder variables such as temperature, pressure and oxygen content. The process can be used with calibrated or uncalibrated internal combustion engines and can be used to capture the effects in variations of engine speed, engine torque, EGR, injection timing, and engine boost levels.

Abstract: A system for protecting an internal combustion engine employing cooled recirculated exhaust gas (EGR) from excessive condensation includes an auxiliary emission control device (AECD) operable to determine when engine operating conditions correspond to a condensing condition resulting in condensation of water at the outlet of the EGR cooler and/or within the intake manifold or intake conduit of the engine. When such conditions occur, the AECD is operable to close the EGR valve and monitor engine operating conditions. When engine operating conditions no longer correspond to the condensing condition, control of the EGR valve is restored to an air handling system associated with the engine.

Abstract: Provided is a control apparatus for a fuel priority type internal combustion engine, including a means of directly or indirectly detecting a variation in air density, for correcting a maximum value of the desired fuel volume on a basis of a result of the detection so as to adjust the relationship between an accelerator opening degree and the desired fuel volume, or a shaft torque value and a desired fuel volume are determined in accordance with a fuel volume corresponding to an internal loss and a fuel volume corresponding to a maximum value of the desired fuel volume.

Abstract: The present invention is configured to maintain a desired emissions level of an engine having an intake manifold and an exhaust manifold, and an exhaust stack is disclosed. The method includes the steps of establishing a desired emissions level, establishing an engine speed, establishing an engine load, establishing at least one characteristic of one of an intake air and an exhaust gas, and determining a fuel command in response to the engine speed, the engine load, and the desired emissions level, the fuel command resulting in the engine maintaining the desired emissions level.

Abstract: A system for protecting an internal combustion engine employing cooled recirculated exhaust gas (EGR) from excessive condensation includes an auxiliary emission control device (AECD) operable to determine when engine operating conditions correspond to a condensing condition resulting in condensation of water at the outlet of the EGR cooler and/or within the intake manifold or intake conduit of the engine. When such conditions occur, the AECD is operable to close the EGR valve and monitor engine operating conditions. When engine operating conditions no longer correspond to the condensing condition, control of the EGR valve is restored to an air handling system associated with the engine.

Abstract: A fuel injection control device for an internal combustion engine, includes a rotational speed sensor for detecting rotational speed of the internal combustion engine, intake air quantity sensor for detecting an air quantity taken into the internal combustion engine, atmospheric pressure sensor for detecting atmospheric pressure, and an engine control unit for estimating an inlet pipe pressure of the internal combustion engine from the detected rotational speed and intake air quantity, computing a fuel injection quantity fuel pressure correction coefficient according to a difference between the estimated inlet pipe pressure and the detected atmospheric pressure, and correcting a fuel injection quantity based on the computed fuel injection quantity fuel pressure correction coefficient.

Abstract: A device for controlling an internal combustion engine having an arrangement for recording operating parameters of the internal combustion engine, such as engine speed, load, and coolant temperature; an arrangement for providing a signal related to a desired drive torque of the internal combustion engine (engine torque) as a function of the recorded performance quantities; and an arrangement for converting the engine torque into control signals for at least one of the variables air supply or fuel supply to the internal combustion engine, as a function of the coolant temperature toot and of a pre definable maximum allowable coolant temperature limit tom-tom, a torque control value being determined which ultimately determines the allowable engine torque.

Abstract: The present invention is configured to maintain a desired emissions level of an engine having an intake manifold and an exhaust manifold, and an exhaust stack is disclosed. The method includes the steps of establishing a desired emissions level, establishing an engine speed, establishing an engine load, establishing at least one characteristic of one of an intake air and an exhaust gas, and determining a fuel command in response to the engine speed, the engine load, and the desired emissions level, the fuel command resulting in the engine maintaining the desired emissions level.

Abstract: A device for controlling an internal combustion engine having an arrangement for recording operating parameters of the internal combustion engine, such as engine speed, load, and coolant temperature; an arrangement for providing a signal related to a desired drive torque of the internal combustion engine (engine torque) as a function of the recorded performance quantities; and an arrangement for converting the engine torque into control signals for at least one of the variables air supply or fuel supply to the internal combustion engine, as a function of the coolant temperature tmot and of a predefinable maximum allowable coolant temperature limit tmotmax, a torque control value being determined which ultimately determines the allowable engine torque.

Abstract: A feed back control system and method for direct injected engines, particularly useful in marine applications to avoid excessive hunting due to the close proximity of the sensor to the fuel injector. Both injection initiation and duration are controlled under most operating conditions. However, under certain conditions such as when only small corrections in the air fuel ratio are required the control is initially maintained by adjusting the injection timing.

Abstract: An air-fuel ratio control system for an internal combustion engine includes an air-fuel ratio sensor arranged in the exhaust system of the engine. An ECU estimates the air-fuel ratio of a mixture supplied to each of the cylinders cylinder by cylinder in response to an output from the air-fuel ratio sensor, by using an observer for observing an internal operative state of the exhaust system, based on a model representative of the behavior of the exhaust system, and calculates cylinder-by-cylinder air-fuel ratio control amounts corresponding respectively to the cylinders for carrying out feedback control of the air-fuel ratio of the mixture supplied to each of the cylinders such that the estimated air-fuel ratio of the mixture supplied to each of the cylinders is converged to a desired value.

Abstract: Pneumatic state estimation operations for estimating gas flow and pressure at pneumatic nodes and flow branches within a reticulated engine system for engine control and diagnostic operations resolves net flow imbalances at specific pneumatic nodes and attributes such imbalances to inaccuracies in pneumatic state estimation. Inaccuracies are corrected as a function of a prior pneumatic state estimate and of a net flow imbalance at the node or a neighboring node for precision engine control and diagnostic operations.

Abstract: A system for controlling fuel metering for a multi-cylinder internal combustion engine having a feedback loop which has an adaptive controller and an adaptation mechanism coupled to said adaptive controller for estimating controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient using internal variables that include the controller parameters .theta., to correct a basic quantity of fuel injection to bring a detected air/fuel ratio to a desired air/fuel ratio determined earlier from the detected air/fuel ratio by a dead time d'. The dead time d' is properly determined to be corresponding to a time k at which the air/fuel ratio is detected. Alternatively, the dead time may be determined to be longer than the proper value to eventually improve vehicle drivability, or determined to be shorter than the proper value to compensate for insufficient fuel adhesion correction.

Abstract: An air-to-fuel ratio control apparatus for an internal combustion engine includes an air-to-fuel ratio sensor of a current limiting type for detecting an air-to-fuel ratio of an air-fuel mixture from a condition of exhaust gas originating from the air-fuel mixture. An air-to-fuel ratio controlling device is operative for performing feedback control in response to an output signal of the air-to-fuel ratio sensor so that the detected air-to-fuel ratio will be substantially equal to a target air-to-fuel ratio. A gain setting device is operative for setting a feedback gain of the air-to-fuel ratio feedback control in response to an atmospheric pressure.

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient that corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of an air/fuel ratio sensor, to a desired air/fuel ratio. The convergence speed of the controller parameters are determined by a gain matrix. The gain matrix is determined in response to at least one of the detected engine operating conditions.

Abstract: A method and apparatus are disclosed for measuring atmospheric pressure in conjunction with an air-fuel ratio sensor of the type comprising a concentration cell with atmospheric air and exhaust electrodes on opposite sides of a solid-state electrolyte having oxygen ion conductivity. During an atmospheric pressure measuring cycle, oxygen ions are pumped from the atmospheric air electrode to the exhaust electrode, in a quantity which is either predetermined at a fixed value, or is sufficient to bring the cell to an equilibrium state. Atmospheric pressure is then calculated from measured emf of the cell, using an experimentally derived functional relationship. In a second embodiment, ions are pumped until a predetermined change of the concentration cell emf is achieved, and atmospheric pressure is determined based on the amount of time required to achieve such change. The atmospheric pressure measuring mode is operated on a time shared basis with the air-fuel ration detection mode.

Abstract: Fuel-vapor evaporating from a fuel tank is led though a vapor pipe and absorbed in a charcoal canister. Though the evaporating rate is influenced by the altitude where the automobile operates, the air-fuel ratio must be controlled within the proper range. This apparatus controls a purge valve in accordance with the purge rate which is determined based on the standard atmospheric pressure and compensated in accordance with the present atmospheric pressure. Therefore, this apparatus can precisely control the amount of purged fuel and the air-fuel ratio.

Abstract: An arrangement determines a voltage which indicates the lambda value of an air/fuel mixture supplied to a combustion engine generating exhaust gas during the operation thereof. The arrangement includes a two-cell oxygen probe mounted in the exhaust gas flow of the engine. The two-cell oxygen probe has an exhaust-gas space for the exhaust gas and an ambient-air space for ambient air. The oxygen probe has a pump cell having two electrodes and a sensing cell having two electrodes. A switchover stage outputs a voltage indicating the electric pump current through the pump cell when a control to the lambda value deviating from one is to be made and outputs that Nernst voltage which is taken off between the electrodes of the sensing cell facing into the ambient air and one of the remaining ones of the electrodes when a control to the lambda value one is to be made. For controlling to the lambda value one, the Nernst voltage supplies a significantly more precise signal than the voltage derived from the pump current.