Abstract: An engine controlling method is provided, which includes, during motoring of the engine, outputting, by an in-cylinder pressure sensor, to a controller a signal indicative of a reference pressure corresponding to a pressure change after an intake valve of a cylinder of the engine is closed when not performing fuel injection, and then injecting, by an injector, fuel for analysis into the cylinder at a specific timing after the intake valve is closed. The method includes, by the controller, acquiring a crank angle period from the intake valve close timing, through the fuel injection, to a timing of the in-cylinder pressure reaching the reference pressure based on signals from the in-cylinder pressure sensor and a crank angle sensor, and determining a property of the injected fuel by comparing the acquired crank angle period with that of a standard fuel based on stored information on a property of the standard fuel.

Abstract: A thermal conductivity detector includes a first pipe passage and an exhaust pipe passage. The first pipe passage is accommodated in a cell block together with a heating device. The exhaust pipe passage has an outlet port at the downstream end, and most of the exhaust pipe passage including the downstream end is drawn out of the cell block. The heating device maintains the space in the cell block at a temperature capable of vaporizing the sample. A filament is accommodated in the first pipe passage. The gas passing through the first pipe passage is discharged out of the thermal conductivity detector through the exhaust pipe passage outlet port. On the inner surface of the exhaust pipe passage, a coating having resistance to a cleaning fluid for removing the adhered substance due to the sample gas is formed.

Abstract: A method of and an apparatus for diagnosing an engine system are provided. An apparatus for diagnosing an engine system including a continuous variable valve duration (CVVD) apparatus and an exhaust gas recirculation (EGR) apparatus may include: an accelerator pedal position sensor detecting a position of an accelerator pedal; a brake pedal position sensor detecting a position of a brake pedal; a vehicle speed sensor detecting a speed of a vehicle; an intake pressure sensor detecting an intake pressure; and a controller determining whether a fuel cut condition is satisfied and determining whether the CVVD apparatus and an EGR valve is in a failure state when the fuel cut condition is satisfied.

Abstract: The present invention is intended to, at the time of directly measuring a flow rate of exhaust gas flowing through an exhaust gas flow path and an air-fuel ratio of the exhaust gas, and on the basis of the flow rate and air-fuel ratio of the exhaust gas, calculating fuel consumption, reduce a measurement error of the fuel consumption. Also, the invention is a fuel consumption calculation unit that, with use of an exhaust gas flow rate obtained by a flow rate sensor provided in an exhaust gas flow path through which exhaust gas of an engine flows, and an air-fuel ratio obtained by an air-fuel ratio sensor provided in the exhaust gas flow path, calculates fuel consumption of the engine, and on the basis of the air-fuel ratio obtained by the air-fuel ratio sensor, changes a value of exhaust gas density used for the calculation of the fuel consumption.

Abstract: In starting the engine, if it is determined that large cams are not completely prepared for all driving cams, valve closing timings of all intake valves are changed by driving the VVT so that all of the cylinders have equal in-cylinder filling efficiency. A fuel injection amount of each cylinder is determined by a feedforward control assuming that the large cams are completely prepared for all of the driving cams. When the valve closing timing of all of the intake valves are changed by driving the VVT to equalize the in-cylinder filling efficiencies of all of the cylinders, all of the cylinders have substantially equal in-cylinder air-fuel ratios.

Abstract: An apparatus for detecting inter-cylinder air-fuel ratio imbalance in an engine is provided. The apparatus includes a turbocharger, a bypass passage configured to bypass a turbine of the turbocharger, a waste gate valve configured to selectively close the bypass passage, an air-fuel ratio sensor installed in a portion of an exhaust passage which portion is located on a downstream side of a junction between a downstream side of the turbine and a downstream side of the bypass passage, and a determination unit programmed to compare a value of a degree of fluctuation in an output from the air-fuel ratio sensor or a parameter correlated therewith with a predetermined threshold to perform inter-cylinder air-fuel ratio imbalance determination. The determination unit is programmed not to perform the imbalance determination when an opening degree of the waste gate valve is equal to or higher than a predetermined reference value.

Abstract: An apparatus for controlling an oxygen sensor may include an oxygen sensor configured to measure the exhaust gas which is generated by the combustion of the engine to generate an oxygen signal, and a controller configured to detect, through the oxygen sensor, a lag of the oxygen signal having responsiveness which is reduced depending on an oxygen amount of the exhaust gas, store information on occurrence factors which cause the lag of the oxygen signal, and increase a current heating quantity of a corresponding specific region about the occurrence factors to reconfirm whether the oxygen signal lags and determine the oxygen sensor as a failure or release a failure detection for the oxygen sensor.

Abstract: Invention suppresses deterioration of emission if there is air-fuel ratio imbalance among cylinders.

Abstract: A method for operating at least one sensor element for detecting at least one property of a gas in a measured-gas space is described. The method comprises at least the following steps: at least one first step, in the first step at least one parameter being ascertained; at least one second step, in the second step the parameter being compared with at least one comparison value, in accordance with that comparison at least one feature being allocated to the sensor element or to at least one part of the sensor element. An apparatus for carrying out the method is also described.

Abstract: An engine oil consumption measuring system includes a multi-cylinder engine with an exhaust system positioned in a test cell. A sampling probe has an end positioned in the exhaust system to receive exhaust. A sample transfer apparatus includes a first end fluidly connected to the sampling probe and a segment positioned in an interior of a furnace. A mass spectrometer includes a specimen probe with an inlet positioned in the segment of the sample transfer apparatus. A particulate filter is positioned in the segment of the sample transfer apparatus upstream from the inlet of the specimen probe. The sample transfer apparatus and the furnace are maintained at temperatures above an oil condensation temperature during testing.

Abstract: An abnormality diagnosis device is for an exhaust gas sensor that detects an air-fuel ratio, or a rich or lean state of exhaust gas from an internal combustion engine and that includes a sensor element having a catalyst layer. The device includes an abnormality diagnosis unit that makes a sensor abnormality diagnosis whereby to change the air-fuel ratio alternately between a rich side and a lean side and to determine whether the exhaust gas sensor is abnormal or not based on response characteristics of the exhaust gas sensor in response to the change of the air-fuel ratio. When making the sensor abnormality diagnosis, the abnormality diagnosis unit calculates the response characteristics of the exhaust gas sensor with exclusion of a sensor output plateau region, which is a region in which an output of the exhaust gas sensor is stagnant due to the catalyst layer.

Abstract: A gas sensor element in an air/fuel ratio sensor includes an element body and a protection layer having two layers (a first layer and a second layer). The gas sensor element has at least one separation portion in the form of a space between the first layer and the second layer. The gas sensor element can temporarily accumulate, in the at least one separation portion, water which adheres to the surface of the protection layer and penetrates into the protection layer. Thus, as compared with a protection layer which is identical in thickness to the protection layer, but does not have separation portions, water adhering to the protection layer is less likely to reach the element body. Therefore, there can be restrained breakage of an end of the element body which could otherwise result from thermal shock stemming from adhesion of water.

Abstract: An apparatus includes an air-fuel ratio sensor installed in an exhaust passage common to a plurality of cylinders in a multicylinder internal combustion engine, and a control apparatus configured to detect an inter-cylinder air-fuel ratio variation abnormality based on a parameter correlated with a degree of variation in output from the air-fuel ratio sensor. The control apparatus is configured to calculate a division crank angle that bisects an area of a region present in at least one of a rich and a lean sides with respect to a mean value of an output waveform from the air-fuel ratio sensor during one cycle of the internal combustion engine or such a predetermined constant value as corresponds to a center of fluctuation in the output waveform and to identify an abnormal cylinder with a deviation of the air-fuel ratio based on the division crank angle.

Abstract: A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on a time delay and line length of each sample of a set of exhaust gas sensor responses collected during a commanded change in air-fuel ratio. In this way, the exhaust gas sensor may be monitored utilizing robust parameters in a non-intrusive manner.

Abstract: The deterioration judgment for an absorption reduction type NOx catalyst (1) is performed quickly and correctly. A catalyst deterioration judging system comprises a supply unit (5) which supplies a reducing agent, a measuring unit (8) which measures a NOx concentration in an exhaust gas at a position downstream from the catalyst (1), a control unit (10) which regulates an amount of the reducing agent so that an air-fuel ratio of the exhaust gas is a lean air-fuel ratio when the reducing agent is supplied from the supply unit (5), and a judging unit (10) which judges deterioration of the catalyst (1) on the basis of the NOx concentration measured by the measuring unit (8) when the amount of the reducing agent is regulated so that the air-fuel ratio of the exhaust gas is the lean air-fuel ratio when NOx is absorbed by the catalyst (1).

Abstract: A method of determining an air:fuel ratio of a combustion process based on information from an oxygen sensor exposed to exhaust gases of the combustion process. A first value is determined indicative of the exhaust gas oxygen content, with the value being based on a resistance of an oxygen sensing portion of the oxygen sensor. A second value is determined indicative of a temperature of the oxygen sensor, which may be based on a resistance of a heater portion of the oxygen sensor. A third value is determined indicative of the air:fuel ratio as a function of the first and second values. Thus, the oxygen level data from the oxygen sensor may be temperature compensated so as to result in a more accurate estimate of the air:fuel ratio. The third value may then be used to control the combustion process, which may be associated with an internal combustion engine.

Abstract: When an internal combustion engine (1) is determined to be in a low-temperature start state (an affirmative determination is made in S120), an air-fuel ratio control apparatus (10) controls the temperature of a downstream detection element (17) of a downstream gas sensor (15) to a downstream target temperature by driving a downstream heater (16) of the downstream gas sensor (15) (S170), and feedback-controls the air-fuel ratio of exhaust gas based on the output of the downstream gas sensor (15) (S190). When the engine (1) is determined not to be in the low-temperature start state (a negative determination is made in S120), the air-fuel ratio control apparatus (10) drives an upstream heater (25) of an upstream gas sensor (22) and feedback-controls the air-fuel ratio of exhaust gas based on the output of the upstream gas sensor (22) (S270).

Abstract: A heater control device of an oxygen concentration sensor is provided in which even in a case where an internal combustion engine is automatically stopped by idle stop control after cold start-up, it is possible to start energization of a heater at an appropriate time.

Abstract: An emission control system for an engine includes a catalyst and an exhaust-gas sensor provided downstream of the catalyst in a flow direction of exhaust gas. The exhaust-gas sensor includes a sensor element that includes a pair of electrodes and a solid electrolyte body located between the electrodes. The emission control system further includes a constant current supply portion that changes an output characteristic of the exhaust-gas sensor by applying a constant current between the electrodes, a rich direction control portion that performs a rich direction control after a fuelling-stop control, and a characteristic control portion that performs a rich responsiveness control during the rich direction control. In the rich direction control, an air-fuel ratio of the exhaust gas is made to be richer. In the rich responsiveness control, the constant current supply portion increases a detection responsiveness of the exhaust-gas sensor with respect to rich gas.

Abstract: A method of estimating an ideal air-fuel ratio in an internal combustion engine, comprises receiving an output of an upstream air-fuel ratio sensor and an output of a downstream air-fuel ratio sensor, the upstream air-fuel ratio sensor being attached to an exhaust gas passage such that it is positioned upstream of a catalyst provided in the exhaust gas passage to purify an exhaust gas, the downstream air-fuel ratio sensor being attached to the exhaust gas passage such that it is positioned downstream of the catalyst; detecting a state in which the catalyst does not store or release oxygen based on the output of the downstream air-fuel ratio sensor; and deciding as an estimated ideal air-fuel ratio in the internal combustion engine an air-fuel ratio detected by the upstream air-fuel ratio sensor when the state in which the catalyst does not store or release oxygen is detected.

Abstract: Providing a PM emission amount estimation device for the diesel engine wherein the accuracy of the correction in correcting the basic level of the PM emission amount by use of the PM emission amount estimation map can be enhanced; and, the PM emission amount particularly during the transient state of the engine operation condition can be accurately computed so as to estimate, with high precision, the PM emission amount and the PM emission accumulated-amount (integrated amount) during the whole engine operation conditions including the transient state as well as the steady state.

Abstract: A protector (100) of a gas sensor (1) includes an inner protector (120) and an outer protector (110). The inner protector accommodates a gas sensor element (10) and has a tubular side wall (122) having inner gas introduction holes (130), and a bottom wall (124). The outer protector has a tubular side wall (112) having outer gas introduction holes (115), a frustum-like taper wall (117) tapering frontward and an outer gas discharge hole (170) formed inside a front end edge (117s) of the taper wall. When SL represents an area defined by the front end edge of the taper wall, the area S of the opening of the outer gas discharge hole satisfies the relational expression ½×SL?S?SL. A cover portion (127) and a bottom wall (124) are partially away from each other along the axial direction, thereby forming side openings (162).

Abstract: A first parameter correlated with a degree of fluctuation of output from an air-fuel ratio sensor is calculated, and whether or not the calculated first parameter has a value between a predetermined primary determination upper-limit value ?1H and a primary determination lower-limit value is determined. Such forced active control as reduces an air-fuel ratio shift in one of the cylinders which is subjected to a most significant air-fuel ratio shift is performed when the calculated first parameter is determined to have a value between the predetermined primary determination upper-limit value and the primary determination lower-limit value. A first parameter is calculated while the forced active control is in execution. The calculated first parameter is compared with a predetermined secondary determination value to determine whether or not variation abnormality is present.

Abstract: A detecting apparatus that detects an abnormality of imbalance of air-fuel ratios among cylinders of a multi-cylinder internal combustion engine, which is equipped with a variable working angle mechanism of an intake valve, the detecting apparatus includes an abnormality detection portion that detects a parameter regarding rotational fluctuations of each of the cylinders and detects whether or not there is an abnormality of imbalance of air-fuel ratios among the cylinders. The abnormality detection portion refrains from determining that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined large working angle range, and determines that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined small working angle range that is on a small working angle side with respect to the large working angle range.

Abstract: An abnormality determination device for an air-fuel ratio sensor includes a differential value calculator and an abnormality determiner. The differential value calculator is configured to calculate a differential value of an output value of the air-fuel ratio sensor which is configured to detect an air-fuel ratio of exhaust gas. The abnormality determiner is configured to determine abnormality of the air-fuel ratio sensor based on a result of comparison between a reference output value of the air-fuel ratio sensor and a predetermined threshold. The reference output value is obtained by the air-fuel ratio sensor when the differential value calculated by the differential value calculator becomes a predetermined value.

Abstract: When an exhaust gas sensor is mounted to an exhaust pipe into which exhaust gas from an engine is introduced, an intermediate member is made to intervene between the exhaust gas sensor and a boss provided in an exhaust manifold, the intermediate member being fastened to the boss by bolts and the exhaust gas sensor being screwed into a screw hole formed in the intermediate member, so that a sensor portion at a front end of the exhaust gas sensor is inserted into the inside of the exhaust pipe. Though the screw hole formed in the intermediate member is to be exposed to high-temperature gas of the exhaust manifold, stainless steel, whose high-temperature strength is high, being used for the intermediate member, a female screw of the screw hole is hard to be softened and an occurrence of torque down can be suppressed.

Abstract: An apparatus for detecting abnormal air-fuel ratio variation among cylinders of a multi-cylinder internal combustion engine includes: a catalyst element that oxidizes hydrogen contained in exhaust gas to remove the hydrogen; a first air-fuel ratio sensor that detects an air-fuel ratio of exhaust gas that has not passed through the catalyst element; a second air-fuel ratio sensor that detects an air-fuel ratio of exhaust gas that has passed through the catalyst element; and a unit that determines whether abnormal air-fuel ratio variation among the cylinders has occurred based on an amount by which a value detected by the second air-fuel ratio sensor is leaner than a value detected by the first air-fuel ratio sensor.

Abstract: A method of determining an air:fuel ratio of a combustion process based on information from an oxygen sensor exposed to exhaust gases of the combustion process. A first value is determined indicative of the exhaust gas oxygen content, with the value being based on a resistance of an oxygen sensing portion of the oxygen sensor. A second value is determined indicative of a temperature of the oxygen sensor, which may be based on a resistance of a heater portion of the oxygen sensor. A third value is determined indicative of the air:fuel ratio as a function of the first and second values. Thus, the oxygen level data from the oxygen sensor may be temperature compensated so as to result in a more accurate estimate of the air:fuel ratio. The third value may then be used to control the combustion process, which may be associated with an internal combustion engine.

Abstract: A method for determining a flux of a gas contained in a medium through a boundary of the medium comprises 1) measuring at least twice with a probe a concentration C of the gas over a time interval ?t and 2) determining the flux of the gas using the following mathematical equation: (I) where F is the gas flux, D is the diffusivity value and ?C is a variation in the gas concentration during the time interval ?t. The probe is placed proximate the boundary. The probe has a gas inlet, a cavity, a gas concentration sensor and a membrane. Each element is in fluid communication with each other so that the gas flows from the gas inlet through the membrane and contacts the gas concentration sensor.

Abstract: An inter-cylinder air-fuel-ratio imbalance determination apparatus includes an air-fuel-ratio sensor in an exhaust passage of an engine. The air-fuel-ratio sensor functions as a limiting-current-type wide range air-fuel-ratio sensor when a voltage is applied, and functions as a concentration-cell-type oxygen concentration sensor when no voltage is applied. The determination apparatus causes the air-fuel-ratio sensor to function as the limiting-current-type wide range air-fuel-ratio sensor, and executes air-fuel ratio feedback control on the basis of the output value of the air-fuel-ratio sensor. When an imbalance determination parameter is obtained, the determination apparatus causes the air-fuel-ratio sensor to function as the concentration-cell-type oxygen concentration sensor, and obtains, as the imbalance determination parameter, a value corresponding to the differentiated value of the output value of the air-fuel-ratio sensor.

Abstract: An air-fuel ratio imbalance among cylinders determining apparatus according to the present invention is applied to a multi-cylinder internal combustion engine in which a compression ratio is variable. The determining apparatus obtains, using at least an output value of an upstream air-fuel ratio sensor disposed for a catalyst, an “imbalance determining parameter” which becomes larger as a degree of an imbalance among “individual cylinder air-fuel ratios” becomes larger, each of the individual cylinder air-fuel ratios being an air-fuel ratio of a mixture supplied to each of cylinders. Further, the determining apparatus determines that an air-fuel ratio imbalance state among cylinders is occurring, when the imbalance determining parameter is larger than a predetermined threshold. The determining apparatus changes the predetermined threshold in accordance with a mechanical compression ratio of the engine.

Abstract: An apparatus and method for detecting an abnormal air-fuel ratio variation between cylinders of a multi-cylinder internal combustion engine in which the output of an air-fuel ratio sensor is acquired at each sampling interval, a parameter correlated with the degree of fluctuation of the sensor output is calculated from a plurality of the acquired sensor outputs, and the presence or absence of the abnormal air-fuel ratio variation between cylinders is determined by comparing the parameter with a determination value. A cylinder air amount is estimated at each sampling interval. Every time the air-fuel ratio sensor output is acquired, the value of the cylinder air amount at the point earlier, by a transport delay time, than the point of the acquisition is determined based on the time-series data, and a corresponding determination value corresponding thereto is calculated. The determination value is determined based on a plurality of the calculated corresponding determination values.

Abstract: In view of a difference in detectability of an air-fuel ratio sensor with respect to each cylinder, a first exhaust system model and a second exhaust system model are defined. The first exhaust system model outputs an air-fuel ratio at the confluent portion based on an air-fuel ratio in a cylinder. The second exhaust system model outputs a detection value of the exhaust gas sensor based on the air-fuel ratio at the confluent portion. A confluent-portion-air-fuel ratio estimating portion designed based on the second exhaust system model estimates the air-fuel ratio at the confluent portion. A combust-air-fuel ratio estimating portion designed based on the first exhaust system model estimates a combust-air-fuel ratio in each cylinder.

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 method and device allow the determination of the concentrations of a plurality of gas species in a gas mixture based on the output signals from a plurality of gas sensors, each of which is sensitive to a plurality of gas species in the gas mixture. The method includes measuring the response of each sensor at a number of levels of each gas in the mixture, determining a mathematical representation of the response characteristics of each sensor, and using the mathematical representation to determine gas concentrations from sensor readings.

Abstract: An air/fuel imbalance (AFIM) diagnostic system comprises a first module, an imbalance determination module, and an imbalance diagnostic module. The first module outputs imbalance data samples based on an oxygen signal provided by an oxygen sensor measuring oxygen in exhaust expelled from cylinders of a cylinder bank. The imbalance determination module determines an AFIM value based on the imbalance data samples. The imbalance diagnostic module selectively diagnoses an AFIM in the cylinder bank based on the AFIM value.

Abstract: This disclosure provides a method for measuring an output characteristic of an air fuel ratio sensor based on an output value of the air fuel ratio sensor at the time of changing a fuel injection amount. Under a predetermined condition, an increase in the fuel injection amount is started from a particular cylinder and the increase in the fuel injection amount is continued for a given time period, or a decrease in the fuel injection amount is started from the particular cylinder and the decrease in the fuel injection amount is continued for the given time period. Therefore, the output characteristic of the air fuel ratio detecting module can be measured with sufficient accuracy, regardless of the contacting strength of emission gas for every cylinder against the air fuel ratio detecting module.

Abstract: A method of estimating the individual fuel air ratio richness of an individual cylinder in an engine by utilizing a single oxygen sensor at the confluence of a plurality of exhaust runners. The method provides for the use of a wide range or switching oxygen sensor at the confluence of a plurality of exhaust runners.

Abstract: A method to determine a performance characteristic of an exhaust system of an engine, where the exhaust system includes an exhaust gas sensor that outputs an exhaust gas signal. A combustion event in a cylinder is fueled at an air-fuel ratio selected to produce exhaust gas that is expected to be distinguishable by the exhaust gas sensor from exhaust gas produced by other combustion events, and used to determine the performance characteristic. The performance characteristic may be an exhaust gas transport time of the exhaust system, a sensitivity characteristic of the exhaust gas sensor, or a fueling correction value necessary to restore fueling to, for example, stoichiometry. Such a method is useful to detect physical changes in the exhaust system such as relocating the exhaust gas sensor, or detect if the exhaust gas sensor is damaged or not operating properly.

Abstract: A monitoring apparatus including a catalytic converter, an upstream air-fuel ratio sensor, and a downstream air-fuel ratio sensor; calculates a sub feedback amount to have an air-fuel ratio represented based on an output value of the downstream air-fuel ratio sensor coincide with a stoichiometric air-fuel ratio; and controls an fuel injection amount based on an output value of the upstream air-fuel ratio sensor and the sub feedback amount, in such a manner that an air-fuel ratio of a mixture supplied to an engine coincides with the stoichiometric air-fuel ratio.

Abstract: A method to determine a performance characteristic of an exhaust system of an engine, where the exhaust system includes an exhaust gas sensor that outputs an exhaust gas signal. A combustion event in a cylinder is fueled at an air-fuel ratio selected to produce exhaust gas that is expected to be distinguishable by the exhaust gas sensor from exhaust gas produced by other combustion events, and used to determine the performance characteristic. The performance characteristic may be an exhaust gas transport time of the exhaust system, a sensitivity characteristic of the exhaust gas sensor, or a fueling correction value necessary to restore fueling to, for example, stoichiometry. Such a method is useful to detect physical changes in the exhaust system such as relocating the exhaust gas sensor, or detect if the exhaust gas sensor is damaged or not operating properly.

Abstract: An air-fuel ratio estimating device can include an amount of fuel injected calculating unit which can estimate the amount of fuel injected GF for each cycle on the basis of a driving time Tout of a fuel injection valve. A proportional constant calculating section determines a proportional constant K, using the estimated charging efficiency CE and the amount of fuel injected Gf, when the output value of a sensor is in a transition region R. When the sensor output value is not in the transition region R, an air-fuel ratio A/F is estimated from the determined proportional constant K, a charging efficiency CE calculated by a calculating section, and the amount of fuel injected Gf.

Abstract: The invention relates to a method and corresponding device for diagnosing the dynamics of an exhaust gas sensor, which is disposed in an exhaust gas duct of an internal combustion engine in the direction of flow of the exhaust gas upstream or downstream of a catalytic converter and with which the air/fuel ratio of the gas mixture supplied to the internal combustion engine is controlled via a control circuit. During diagnosis, provision is made for at least one actuator intervention to be specified by means of a control algorithm of a diagnostic controller specifically m the direction of an asymmetric behavior, which is achieved by an extension of one of the two ramps, until the actuator intervention is compensated by an asymmetric dynamic error of the exhaust gas sensor, a reaction to said actuator intervention being used as criterion for assessing an asymmetric dynamic error of said exhaust gas sensor.

Abstract: In an exhaust gas sensor control system and control method, the exhaust pipe wall temperature is estimated based on the measured exhaust gas temperature measured, the exhaust gas flow rate, and the measured outside air temperature, with reference to a supplied heat quantity calculation map, wall temperature added value map, and a wall temperature subtracted value map. Then the dew-point of the exhaust pipe is calculated based on the air-fuel ratio of the air flow amount to the weight of fuel, and a condensed water added amount is calculated based on the relative wall temperature and the exhaust gas flow amount. The amount of condensed water is then estimated by summing the calculated condensed water added amounts.

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: An apparatus and method for detecting an abnormal air-fuel ratio variation between cylinders of a multi-cylinder internal combustion engine in which the output of an air-fuel ratio sensor is acquired at each sampling interval, a parameter correlated with the degree of fluctuation of the sensor output is calculated from a plurality of the acquired sensor outputs, and the presence or absence of the abnormal air-fuel ratio variation between cylinders is determined by comparing the parameter with a determination value. A cylinder air amount is estimated at each sampling interval. Every time the air-fuel ratio sensor output is acquired, the value of the cylinder air amount at the point earlier, by a transport delay time, than the point of the acquisition is determined based on the time-series data, and a corresponding determination value corresponding thereto is calculated. The determination value is determined based on a plurality of the calculated corresponding determination values.

Abstract: When a wastegate valve, which opens and closes an exhaust bypass passage bypassing an exhaust turbine, is open, exhaust gases of respective cylinders bypass the exhaust turbine and pass a sensing point of an air-fuel ratio sensor downstream of the exhaust turbine. Accordingly, the exhaust gases of the respective cylinders can be avoided from being mixed by the exhaust turbine, so an influence of an inter-cylinder variation in an air-fuel ratio due to an inter-cylinder imbalance abnormality becomes apt to appear in an output waveform of the air-fuel ratio sensor. Therefore, existence or nonexistence of the inter-cylinder imbalance abnormality is determined based on the output of the air-fuel ratio sensor when the wastegate valve is open. Eventually, the existence or nonexistence of the inter-cylinder imbalance abnormality can be determined accurately, thereby improving detection accuracy of the inter-cylinder imbalance abnormality.

Abstract: It is an object of the present invention to provide a gas concentration detection apparatus that is capable of forming an accurate activity judgment when a gas concentration detection cell begins to detect gas concentration with high accuracy. When warm-up begins at time t0 in a NOx concentration detection apparatus that achieves NOx concentration detection with a NOx sensor cell after excess oxygen is discharged by an oxygen pump cell, a NOx sensor cell output begins to rise at time t1. Subsequently, at time t2, an oxygen pump cell output begins to rise. An inflection point appearing in the NOx sensor cell output is then located. At time t5 at which the inflection point appears, an activity judgment about the NOx sensor cell is formed.

Abstract: This disclosure provides a method of detecting a cylinder-to-cylinder gap abnormality of an air fuel ratio with sufficient accuracy according to an individual specificity of an air fuel ratio detecting module. Particularly, the method may be used for an engine to detect the cylinder-to-cylinder gap abnormality of the air fuel ratio of supplied air fuel mixture abnormality based on an output value of a linear O2 sensor. Under a first predetermined condition, an output characteristic of the sensor is measured. The measured output characteristic is compared with a reference characteristic set in advance to calculate a correction value for correcting the sensor output according to the individual specificity of the sensor. Subsequently, under a second predetermined condition, the sensor output value is corrected based on the calculated correction value to detect the abnormality based on the corrected output value of the sensor.

Abstract: A device and a method for controlling an internal combustion engine are provided, in which the fuel quantity to be injected is controlled as a function of a Lambda signal. A setpoint value for the Lambda signal is specified on the basis of at least one maximally permitted exhaust-gas temperature value.