Abstract: The present disclosure relates to methods for determining a maximum power setpoint for a wind turbine comprising determining a temperature of one or more wind turbine components, and determining one or more component temperature errors by determining a difference between the temperatures of the wind turbine components and a corresponding threshold temperature for the components. The methods further comprise determining a present power output of the wind turbine and determining the maximum power setpoint at least partially based at least on the component temperature errors, and on a present power output of the wind turbine. The present disclosure further relates to methods for determining a setpoint reduction and to wind turbine control systems and wind turbines configured for such methods.

Abstract: A fuel injection timing is made later and/or a fuel injection amount is made larger in a target cylinder to be subjected to explosive combustion subsequently, when a required rotation time that is a time required for rotation of an output shaft by a predetermined rotational angle is equal to or longer than a time threshold than when the required rotation time is shorter than the time threshold, at the time of predetermined startup control in which an engine and a clutch are controlled such that fuel injection and ignition in the engine are resumed from a state where the supply of fuel to the engine is cut off and the clutch is released and that the clutch is then engaged.

Abstract: Aspects of the technology relate to exception handling for a vehicle. For instance, a current trajectory for the vehicle and sensor data corresponding to one or more objects may be received. Based on the received sensor data, projected trajectories of the one or more objects may be determined. Potential collisions with the one or more objects may be determined based on the projected trajectories and the current trajectory. One of the potential collisions that is earliest in time may be identified. Based on the one of the potential collisions, a safety-time-horizon (STH) may be identified. When a runtime exception occurs, before performing a precautionary maneuver to avoid a collision, waiting no longer than the STH for the runtime exception to resolve.

Abstract: Methods and systems are provided for diagnostics of exhaust gas recirculation (EGR) components including an EGR pressure sensor. In one example, a method may include comparing a current relationship between an output of the EGR pressure sensor and a manifold air pressure (MAP) and a pre-calibrated relation between the output of the EGR pressure sensor and the MAP to detect degradation of the EGR pressure sensor.

Abstract: An EGR valve deterioration degree calculation system configured to calculate a degree of deterioration of an EGR valve includes an execution device. The execution device is configured to perform: a pressure acquisition process; a pressure change amount calculation process of calculating a pressure change amount associated with an operation of opening and closing the EGR valve; a differential pressure calculation process of calculating a differential pressure between an upstream side of the EGR valve and a downstream side of the EGR valve when the EGR valve is in a closed state; and a deterioration degree calculation process of calculating the degree of deterioration of the EGR valve based on the pressure change amount and the differential pressure.

Abstract: Methods and systems that monitor an actuator state of wear. One or more observations are made as to one or more extremum positions of the actuator to determine a reference extremum position when the actuator is not worn. As the actuator becomes worn, the difference between a present extremum position and the reference is used to monitor actuator wear. Actuator wear may be observed to identify or predict a need for maintenance or replacement, and/or may be used in determining health impacts of control system solutions.

Abstract: An EGR device is provided with: an EGR passage for allowing a portion of exhaust gas from an engine to flow to an intake passage; an EGR valve for adjusting an EGR flow rate through the EGR passage; a throttle valve provided in the intake passage; and an electronic control device which calculates a fully closed reference intake pressure based on an operating state of the engine during EGR valve fully-closing, and which diagnoses an abnormality due to valve-opening locking of the EGR valve based on the calculated fully closed reference intake pressure. The ECU determines a foreign matter biting abnormality of the EGR valve based on the intake pressure, and based on the result of adding the fully closed reference intake pressure, calculated according to the rotational speed and the load of the engine, to an intake-pressure increase allowance calculated according to the rotational speed.

Abstract: Aspects of the technology relate to exception handling for a vehicle. For instance, a current trajectory for the vehicle and sensor data corresponding to one or more objects may be received. Based on the received sensor data, projected trajectories of the one or more objects may be determined. Potential collisions with the one or more objects may be determined based on the projected trajectories and the current trajectory. One of the potential collisions that is earliest in time may be identified. Based on the one of the potential collisions, a safety-time-horizon (STH) may be identified. When a runtime exception occurs, before performing a precautionary maneuver to avoid a collision, waiting no longer than the STH for the runtime exception to resolve.

Abstract: In an engine device, when executing normal control that performs fuel injection and ignition as control of an engine, a controller estimates, in the case of a stoichiometric air-fuel ratio, an exhaust gas temperature based on first thermal energy that is based on a combustion gas temperature, a combustion gas quantity, and specific heat of combustion gas, estimates, in the case of a lean air-fuel ratio, the exhaust gas temperature based on the first thermal energy and second thermal energy that is based on an air temperature, a surplus air quantity, and specific heat of air, and estimates, in the case of a rich air-fuel ratio, the exhaust gas temperature based on the first thermal energy and third thermal energy that is based on a fuel temperature, a surplus fuel quantity, specific heat of fuel, and evaporation latent heat of fuel.

Abstract: Methods and systems are provided for identifying degraded exhaust gas temperature (EGT) sensor responses. In one example, a method may include cycling an engine between a higher temperature operating mode and a lower temperature operating mode while maintaining engine torque output across the higher temperature operating mode and the lower temperature operating modes, both the higher temperature operating mode and the lower temperature operating mode providing stoichiometric exhaust gas to a downstream catalyst, and characterizing a response behavior of an EGT sensor based on output of the EGT sensor during the cycling. In this way, stepwise exhaust gas temperature changes are produced for characterizing the EGT sensor response without disrupting emissions and torque control.

Abstract: An engine system includes an injector, an EGR device (including an EGR valve having a step motor) to recirculate part of exhaust gas of an engine as EGR gas to the engine, and an electronic control unit (ECU) to control the injector, the EGR valve, and others based on an operating state of the engine. The ECU is configured to diagnose foreign-matter lodging abnormality of the EGR valve and a lodged foreign-matter diameter based on detected intake pressure during engine deceleration. When existence of the abnormality and the foreign-matter diameter are determined, the ECU controls the step motor to hold the EGR valve at a first opening degree smaller than a second opening degree needed to remove a foreign matter before fuel cut to the engine by the injector.

Abstract: Methods and systems are provided for determining a dilution of recirculated gases, including blowthrough air, combusted exhaust gas, and fuel vapor, in a split exhaust engine. In one example, the dilution rate may be calculated using a feedforward model that includes determining a pressure differential across a region in an intake passage, mapped engine parameters such as gas temperature, and exhaust valve timing. Engine operations such as spark advance and fuel injection may be adjusted according to the modeled rate to reduce engine knock and improve combustion efficiency.

Abstract: Diagnostic systems and methods for detecting leaks in an exhaust gas recirculation (EGR) system of an engine of a vehicle utilize an upstream oxygen (O2) sensor disposed in an exhaust system of the engine upstream from an EGR port of the EGR system and configured to measure an upstream O2 concentration of exhaust gas produced by the engine, a downstream O2 sensor disposed in the exhaust system downstream from the EGR port and configured to measure a downstream O2 concentration of the exhaust gas, and a controller configured to receive the measured upstream and downstream O2 concentrations from the upstream and downstream O2 sensors, respectively, and detect a leak in the EGR system when a difference between the measured downstream and upstream O2 concentrations exceeds a diagnostic threshold.

Abstract: An exhaust gas recirculation system includes an intake manifold, an exhaust manifold, an EGR cooler, an EGR exhaust conduit and an EGR intake conduit having a diffuser. The intake manifold and the exhaust manifold are affixed to an engine head. The intake and exhaust manifolds are each in fluid communication with a plurality of combustion chambers defined by the engine head and an engine block. The EGR cooler includes a EGR cooler inlet and a EGR cooler outlet wherein the EGR exhaust conduit fluidly couples the exhaust manifold to the EGR cooler inlet. The EGR intake conduit includes a first end and a second end wherein the first end is affixed to the EGR cooler outlet and the second end is affixed to an intake passageway for the intake manifold. The diffuser includes a plurality of fins affixed to the second end and extending into the intake passageway.

Abstract: Methods and systems are provided for adjusting an exhaust gas recirculation (EGR) valve based on a final EGR estimate. In one example, a method may include adjusting the EGR valve based on a final EGR flow estimate, the final EGR flow estimate based on a first EGR flow estimated with a differential pressure sensor across the EGR valve, a second EGR flow estimated with an intake oxygen sensor, and accuracy values of each of the first and second EGR flows. The accuracy value may be based on engine operating conditions during estimation of the first and second EGR flows.

Abstract: A method for adjusting an exhaust heat recovery valve is presented. In one embodiment, the method may control an amount of boost provided by a turbocharger to an engine.

Abstract: In the engine including an MPL-EGR system having an HPL-EGR mechanism 6 and an LPL-EGR mechanism 7, a pressure difference between upstream side pressure and downstream side pressure of a low pressure EGR cooler 73 provided in the LPL-EGR mechanism 7 is detected by a pressure difference sensor 89. When an actual pressure difference value detected is higher than a reference pressure difference value in a state where no blocking occurs in the LPL-EGR mechanism 7, and the deviation amount therebetween reaches a predetermined amount, it is determined that the blocking occurs in the inside of the low pressure EGR cooler 73. In contrast, when the actual pressure difference value detected is lower than the reference pressure difference value, and the deviation amount therebetween reaches a predetermined amount, it is determined that the blocking occurs in the inside of the pipe members 74 and 75 except the low pressure EGR cooler 73.

Abstract: An absolute value of a deviation of an actual EGR ratio, calculated in a current operational status of an engine 1, from a target EGR ratio set on the basis of current operational status of the engine 1 is acquired and is multiplied by a quotient, as gain, acquired from division of a feedback correction amount of opening degree of an EGR valve 12 by an upper limit of the feedback correction amount to determine normality when an acquired product is close to “0” and determine higher degree of abnormality the further the product is away from “0”.

Abstract: An internal combustion engine is equipped with an EGR system that includes an EGR heat exchanger. A method for monitoring the EGR heat exchanger includes monitoring an EGR gas inlet temperature to the EGR heat exchanger, an EGR gas outlet temperature from the EGR heat exchanger, a coolant temperature and a mass EGR flowrate through the EGR heat exchanger for a present engine operating point. An actual thermal effectiveness of the EGR heat exchanger for the present engine operating point is determined. A maximum heat transfer coefficient for the EGR side of the EGR heat exchanger is determined for the present engine operating point. The EGR heat exchanger is regenerated when the actual heat transfer coefficient differs from the maximum heat transfer coefficient for the present engine operating point.

Abstract: The invention relates to a method of controlling a combustion engine (1) comprising at least one cylinder (2) and a manifold (3) and an exhaust gas recirculation (EGR) circuit including an EGR valve. The EGR valve (6) is controlled by carrying out the following stages: a) measuring a pressure difference ?P in a portion of the exhaust gas recirculation circuit including the EGR valve; b) selecting a burnt gas fraction set point BGRsp in the intake manifold (3); c) calculating an opening set point for the EGR valve (6) from a pressure drop relation applied in a portion of the exhaust gas recirculation circuit including the EGR valve, depending on difference ?P at the EGR valve and on the burnt gas fraction set point BGRsp in the intake manifold; and d) controlling the EGR valve (6) as a function of the opening set point of EGR valve (6).

Abstract: A current-control profile may be built from a sequence of phases in which the current is controlled in a defined manner. The electrical behavior of these phases may be configured within a list, which contains one entry, or slot, for each phase and which may be stored in a memory device. The order for stepping through the list is not hard-wired into the control circuit. Instead, such an order is part of the configuration for each entry, or slot, itself. Each entry/slot contains the information about the next phase, or the next possible phases depending upon the occurrence of any trigger events. In this way, the list of entries/slots is linked dynamically by the configuration thereby allowing for generation, in a flexible way, of current profiles with different characteristics and different numbers of phases and sequences.

Abstract: A method for specifying a malfunction of an exhaust gas recirculation system of an internal combustion engine of a motor vehicle, including: setting a first operating point of the engine and a first operating state of the fresh air/exhaust gas system as vehicle conditioning in a first measurement setting; measuring volumetric efficiencies of the engine for the first measurement setting and for at least one additional measurement setting, and comparing the measured volumetric efficiencies with an engine characteristics map stored in a memory unit for volumetric efficiency values of the engine, and ascertaining whether a malfunction is present during the exhaust gas recirculation process based on the comparison; and specifying the malfunction of the exhaust gas recirculation system while taking into account the measuring results for the first measurement setting and for the at least one additional measurement setting and the stored engine characteristics map for volumetric efficiency values.

Abstract: A gas analyzer system to determine the concentration of gases in an automotive air conditioning system comprising: an infrared multi-detector device equipped with a gas analysis chamber; an emitter source emitting infrared radiation in the analysis chamber; infrared multi-detectors generating an electrical measurement quantity based on the absorption of radiation by the gas; a suction pump creating a depression inside the analysis chamber; and an electronic control unit determining a main automotive refrigerant gas concentration and the contaminant gases concentration, based on electrical measurement quantities provided by the multi-detectors and a reference electrical quantity. The control unit controls the pump to suck the gases in the analysis chamber until a condition of absence of gases is achieved, wherein the internal pressure of the chamber reaches a minimum pressure, and then determines the reference electrical quantity, based on the electrical quantity generated in the condition of absence of gases.

Abstract: In a reforming driving mode, while the EGR valve is opened to recirculate a part of exhaust gas into the intake pipe, a reforming-fuel injector injects a reforming-fuel into an exhaust gas flowing through an EGR pipe. The injected reforming-fuel is vaporized and flows into the fuel-reforming catalyst. The fuel-reforming catalyst reforms the fuel in the exhaust gas into the fuel having high combustibility. In the reforming driving mode, the computer determines whether an air-fuel ratio within the normal range. Based on this result, the computer determines whether the reforming-fuel injector has a malfunction. When the reforming-fuel injector has a malfunction, a fail-safe processing is conducted to prohibit the reforming-fuel injector from injecting the reforming-fuel.

Abstract: An exhaust gas recirculation diagnosis device may include an EGR module that supplies an intake manifold with exhaust gas from an exhaust manifold, a MAP (manifold absolute pressure) sensor that measures pressure of the intake manifold, and a control portion that controls the EGR module such that the flow rate of the exhaust gas that is supplied from the exhaust manifold to the intake manifold is controlled by stages and monitors the value of the MAP sensor in a fuel cut off condition to diagnose whether the EGR module is faulty. The exhaust gas recirculation diagnosis device uses MAP sensor to perform exhaust gas recirculation and to diagnose the fault of the exhaust gas recirculation device.

Abstract: A method for diagnosing an actuator for a boost pressure system of an internal combustion engine, in which the actuator is controlled using a triggering signal, and a state variable of the boost pressure system which is at least an indirect function of the triggering signal is detected. The triggering signal is periodic, and a curve of the values of the state variable is analyzed with regard to at least one periodic characteristic.

Abstract: A method and device for diagnosing a low pressure exhaust gas recirculation system (LPEGRS) of an internal combustion engine having an intake area for supplying fresh air which includes in succession in the flow direction a first section having a low pressure in which an air mass flow sensor is situated, a compressor and a second section having a high pressure, the engine exhaust area including a second section having a low exhaust gas pressure, and the LPEGRS which has an adjustable LPEGR valve recirculating at least a portion of the exhaust gas in the second section of the exhaust area to the first section of the intake area.

Abstract: An absolute value of a deviation of an actual EGR ratio, calculated in a current operational status of an engine 1, from a target EGR ratio set on the basis of current operational status of the engine 1 is acquired and is multiplied by a quotient, as gain, acquired from division of a feedback correction amount of opening degree of an EGR valve 12 by an upper limit of the feedback correction amount to determine normality when an acquired product is close to “0” and determine higher degree of abnormality the further the product is away from “0”.

Abstract: A method of modeling and testing the effectiveness of an EGR cooler. The cooler effectiveness is mathematically modeled as a function of various temperatures and over an operation history that includes one or more engine shut-downs.

Abstract: An apparatus includes an operating conditions module that interprets a number of compressor operating parameters; a compressor flow module that determines a compressor inlet flow in response to the number of compressor operating parameters; and a fresh air flow module that provides a fresh air flow value in response to the compressor inlet flow. The operating conditions module further interprets a current mass air flow value, and the apparatus further includes a mass air flow sensor trimming module that adjusts a mass air flow sensor drift value in response to the current mass air flow value and the fresh air flow value. The apparatus includes a diagnostics module that determines a mass air flow sensor is failed in response to the current mass air flow value and the fresh air flow value.

Abstract: A system for diagnosing a switchable roller finger follower (SRFF) and an oil control valve (OCV) includes a signal monitoring module and a fault detection module. The signal monitoring module receives at least one of an individual cylinder fuel correction (ICFC) signal and an air/fuel ratio imbalance (AFIM) signal when: an engine speed signal is within a predetermined range of speed; an engine load signal is within a predetermined range of load; and a charcoal canister vapor signal is within a predetermined range of flow rate. The fault detection module detects a fault of at least one of a SRFF and an OCV based on an exhaust gas recirculation value and at least one of the ICFC and AFIM signals. The ICFC and AFIM signals are generated based on: an engine position signal; and at least one of an oxygen signal and a wide range air fuel signal.

Abstract: An apparatus for determining a condition of an exhaust gas recirculation (EGR) cooler of an internal combustion engine includes a clean EGR cooler module that is configured to estimate the temperature of exhaust gas exiting a clean EGR cooler. The apparatus also includes a fouled EGR cooler module that is configured estimate the temperature of exhaust gas exiting a fouled EGR cooler. Further, the apparatus includes an EGR cooler effectiveness module that is configured to determine a normalized effectiveness of the EGR cooler based on the estimated temperature of exhaust gas exiting a clean EGR cooler and the estimated temperature of exhaust gas exiting a fouled EGR cooler. Additionally, the apparatus includes an EGR cooler condition module that is configured to determine a condition of the EGR cooler based on the normalized effectiveness of the EGR cooler.

Abstract: A method to operate an electronic controlled internal combustion engine to perform on board NOx emissions level diagnostics. In one embodiment, the method may include operating the engine to maintain a predetermined temperature for a predetermined period of time, determining whether the engine operating status is stable for one of cruise control, idle engine speed, engine torque, or high idle regeneration for a predetermined period of time, cycling the EGR valve between a first position for a predetermined period of time and then in a second position for a predetermined period of time, a determining a change in engine out NOx levels to determine whether an engine component or system is malfunctioning.

Abstract: An abnormality detection device for detecting abnormalities in an EGR device for an internal combustion engine with a supercharger. The abnormality detection device includes an O2 sensor which is installed in an EGR path and disposed on the exhaust path side relative to the EGR valve, and an A/F sensor which is installed in the exhaust path and disposed downstream of a connecting portion between the exhaust path and the EGR path.

Abstract: A control system (36) for comparing engine speed data to an engine speed threshold above which the engine is considered to be running (40), for comparing engine temperature data to an engine temperature threshold (60), and once engine speed data has become greater than the engine speed threshold, for causing engine torque to be limited to an engine torque limit until the first to occur of: engine temperature data exceeding the engine temperature threshold, a first timer (44), started upon engine speed data having become greater than the engine speed threshold, having timed to a time that is a function of engine temperature data, and a second timer (54), started upon engine speed data having become greater than the engine speed threshold and engine oil pressure data having become greater than an engine oil pressure threshold, having timed to a time that is also a function of engine temperature data.

Abstract: A method and a system for monitoring exhaust gas recirculation are provided that measures a state of an engine, judges an applied system between a high-pressure EGR system and a low-pressure EGR system according to the measured state of the engine, and judges whether a system is erroneous by measuring the position of an EGR valve of an unapplied EGR system and comparing the position with a predetermined reference position.

Abstract: An intake system for an internal combustion engine includes an intake passage connected with an intake port of the internal combustion engine; an EGR passage merged with the intake passage at a junction portion; a gas sensor attached to the intake passage and configured to detect a concentration of specific gas; and a control section configured to control the internal combustion engine on the basis of an output signal of the gas sensor. A diameter-enlarged portion having an inner diameter larger than an inner diameter of the junction portion is formed at a portion of the intake passage which is located on a downstream side of the junction portion. The gas sensor is located downstream from the diameter-enlarged portion.

Abstract: In a method for diagnosing a valve in a fluid supply line to a suction line of an air system of a combustion engine, the fluid supply line being is part of an exhaust-gas recirculation system or a crankcase ventilation system, when the valve is actuated, a first pressure in the suction line is monitored for change, and an error of the valve is detected if the change of the first pressure lies outside a specific reference range when the valve is actuated.

Abstract: A method for estimating a cylinder air charge for an internal combustion engine includes determining a first volumetric efficiency corresponding to engine operation with an open exhaust gas recirculation valve, determining a second volumetric efficiency corresponding to engine operation with a closed exhaust gas recirculation valve, determining a cylinder air charge using a selected one of the first and second volumetric efficiencies.

Abstract: A valve freeze control apparatus for an internal combustion engine includes a concentration sensor, a valve, a freeze control device, and a start determination unit. The concentration sensor is adapted to detect an alcohol concentration of fuel supplied to the internal combustion engine. The valve is provided in one of an intake passage and an exhaust passage of the internal combustion engine, wherein the valve controls flow of air that passes through the one of the intake and exhaust passages. The freeze control device is adapted to limit malfunction of the valve caused by freeze of water in exhaust gas, and the water has been attached to the valve. The start determination unit determines to start the freeze control device when the alcohol concentration detected by the concentration sensor is equal to or greater than a reference value.

Abstract: A method and a system for monitoring exhaust gas recirculation are provided that measures a state of an engine, judges an applied system between a high-pressure EGR system and a low-pressure EGR system according to the measured state of the engine, and judges whether a system is erroneous by measuring the position of an EGR valve of an unapplied EGR system and comparing the position with a predetermined reference position.

Abstract: An exhaust gas recirculation diagnosis device may include an EGR module that supplies an intake manifold with exhaust gas from an exhaust manifold, a MAP (manifold absolute pressure) sensor that measures pressure of the intake manifold, and a control portion that controls the EGR module such that the flow rate of the exhaust gas that is supplied from the exhaust manifold to the intake manifold is controlled by stages and monitors the value of the MAP sensor in a fuel cut off condition to diagnose whether the EGR module is faulty. The exhaust gas recirculation diagnosis device uses MAP sensor to perform exhaust gas recirculation and to diagnose the fault of the exhaust gas recirculation device.

Abstract: An EGR ratio measuring device comprises a pair of nondispersive infrared gas analyzers that correct a water influence and measure a concentration of CO2 in a gas containing water, an intake air introduction line that is connected to an intake air pipe of an internal combustion engine and introduces a part of the intake air into one nondispersive infrared gas analyzer without removing the water, an exhaust gas introduction line that is connected to an exhaust gas pipe of the internal combustion engine and introduces a part of the exhaust gas into the other nondispersive infrared gas analyzer without removing the water, and a temperature adjusting mechanism that keeps a temperature of whole of the introduction lines and a temperature of the nondispersive infrared gas analyzers so as not to condense dew.

Abstract: An internal combustion engine includes at least two cylinders, an intake duct, an exhaust gas section and an exhaust gas recirculation line. The cylinders include a combustion chamber. The intake duct communicates with the combustion chambers via a cylinder inlet channel of the intake duct depending upon a switch position of a gas inlet valve. The exhaust gas section communicates with the combustion chambers depending upon a switch position of at least one gas outlet valve. Exhaust gas is guided back to the inlet channels via the exhaust gas recirculation line dependent upon a switch position of the exhaust gas recirculation valve. To detect a mixing air temperature in the inlet channels, a mixing air temperature sensor is provided. The determined mixing air temperatures are compared. Exhaust gas guided back due to uneven distribution is identified if a difference between the determined mixing air temperature is greater than a predetermined threshold value.

Abstract: A method for diagnosing a failure of an EGR circuit of an engine including an EGR exchanger, an EGR valve, a bypass duct of the EGR exchanger, and a bypass flap arranged upstream from the EGR exchanger and the bypass duct to adjust a proportion of exhaust gases flowing therethrough. The EGR circuit can be activated according to a cooled mode, in which the flap is shut, or according to a bypass mode, in which the flat is open. The method carries out, during a diagnosis phase, two activations of the flap, and measures an average of variations of the EGR gas temperature at an outlet of the EGR exchanger during the diagnosis phase.

Abstract: A determination is made more simply as to a malfunction of a low pressure EGR device that supplies an EGR gas from a low pressure EGR passage connecting between an exhaust passage at a location downstream of a turbine and an intake passage.

Abstract: An object of the present invention is to accurately detect an abnormality in an EGR device for an internal combustion engine with a supercharger, or more specifically, the inability of an EGR valve to fully close due, for instance, to trapped foreign matter. To achieve the object, the present invention provides an abnormality detection device for the EGR device. The abnormality detection device includes an O2 sensor which is installed in an EGR path and disposed on the exhaust path side relative to the EGR valve, and an A/F sensor which is installed in the exhaust path and disposed downstream of a connecting portion between the exhaust path and the EGR path. The abnormality detection device uses a signal output from the O2 sensor and a signal output from the A/F sensor to judge whether the EGR device is abnormal.

Abstract: An engine processor (38) processes data for inferring temperature of exhaust gas at an exhaust manifold (18) of an internal combustion engine (10) whose exhaust system (16) contains an after-treatment device (26, 28) for treating exhaust gas and a sensor (30) for providing data for temperature of exhaust gas entering the after-treatment device. The processor processes data from the sensor and other data to infer temperature of exhaust gas at the exhaust manifold by executing an algorithm (FIGS. 3 and 4) that models temperature of exhaust gas at the exhaust manifold as a function of data from the sensor and the other data, including certain constants, certain geometry of the exhaust system, and certain variables related to operation of the engine.

Abstract: A system and method are provided for estimating an instantaneous EGR mass flow rate corresponding to a flow rate of exhaust gas through an exhaust gas recirculation (EGR) conduit fluidly coupled between an exhaust manifold and an intake manifold of an internal combustion engine with an EGR cooler positioned in-line with the EGR conduit. An operating position of the engine is monitored, and the instantaneous EGR mass flow rate is estimated at each of a plurality of fixed increments of the engine position based on EGR cooler outlet temperature, intake manifold pressure and a pressure differential across a flow restriction disposed in-line with the exhaust gas conduit between the EGR cooler and the intake manifold.

Abstract: In a method for operating an internal combustion engine having exhaust gas recirculation, air is supplied to at least one combustion chamber via an intake manifold at least partially closable with the aid of a final control element, and a part of the exhaust gases flowing into an exhaust pipe is conducted via an EGR channel, which is at least partially closable with the aid of an EGR valve unit, into an area of the intake manifold, which lies between the final control element and the combustion chamber. A first variable, which characterizes the mass flow of the gas conducted through the EGR channel, is ascertained from a set of state variables of the internal combustion engine, which apply for an operating state in which the engine is in overrun operation and the final control element is essentially closed.