Abstract: A control module for a vehicle includes a correction module that generates a correction signal based on a regeneration state of an exhaust system of the vehicle and based on a received environmental signal. The environmental signal includes at least one of an altitude value, an ambient temperature, and an air flow value. The air flow value corresponds to air flow across an external area of the exhaust system. A first post injection module generates a first post injection signal. A second post injection module adjusts the first post injection signal based on the correction signal to generate a second post injection signal.

Abstract: Enabled is reliable detection of abnormality in a NOx emission control system. Disclosed is a method for detecting abnormality in an exhaust emission control device with a reducing agent (urea water 17) being added to selective reduction catalyst 10 incorporated in an exhaust pipe 9 so as to reduce and purify NOx. Temperature of the catalyst during an operation period is monitored to record a cumulative time for each of temperature zones. On the basis of the recorded cumulative time for each of the temperature zones, a deterioration coefficient of NOx reduction performance is determined for each of the temperature zones. A standard NOx reduction ratio predetermined for each of the temperature zones is multiplied by the determined deterioration coefficient for each of the temperature zones to update the standard NOx reduction ratio.

Abstract: An air-fuel ratio control apparatus of an internal combustion engine includes first and second catalysts 10 and 12, first air-fuel ratio acquiring means 8 provided up-stream of the first catalyst, for acquiring an air-fuel ratio of exhaust gas; second air-fuel ratio acquiring means 11 for acquiring an air-fuel ratio of the exhaust gas flowing into the second catalyst, and air-fuel ratio controlling means 13 for controlling an air-fuel ratio according to the air-fuel ratios acquired by the first and second air-fuel ratio acquiring means, and the air-fuel ratio controlling means is provided with lean control means 13 for controlling an air-fuel ratio until the second catalyst becomes lean after completion of a fuel quantity increasing operation of the engine, and intermediate lean control means 13 for performing control to change the air-fuel ratio to a lean air-fuel ratio within the range enough to make the first catalyst lean and not enough to make the second catalyst lean, between the fuel quantity increasin

Abstract: Deterioration of a catalyst provided in an exhaust system of the engine is determined. Air-fuel ratio sensors are provided in the upstream side and the downstream side of the catalyst. Air-fuel ratio is changed. Based on the sensor outputs in the upstream die and the downstream side of the catalyst, a parameter of a catalyst model representing a state of the catalyst is identified. The parameter is compared with a threshold to determine a state of the catalyst.

Abstract: An air fuel ratio control apparatus for an internal combustion engine can improve accuracy in catalyst degradation diagnosis. The apparatus includes a first air fuel ratio feedback control section that adjusts the air fuel ratio of a mixture supplied to an engine in accordance with an output of an upstream air fuel ratio sensor and a predetermined control constant thereby to make the air fuel ratio periodically oscillate in rich and lean directions, an average air fuel ratio oscillation section that operates the control constant based on an amount of oxygen occlusion of a catalyst so that an average air fuel ratio obtained by averaging the periodically oscillating air fuel ratio is caused to oscillate in the rich and lean directions, and a catalyst degradation diagnosis section that diagnoses catalyst degradation based on correlation between the oscillation of the average air fuel ratio and an output of the downstream oxygen sensor.

Abstract: An air fuel ratio control apparatus for an internal combustion engine can freely change an oscillation width of an amount of oxygen occlusion so as to adapt to or diagnose catalyst degradation without changing the settings of the period or width of the air fuel ratio oscillation. The apparatus includes a first air fuel ratio feedback control section that adjusts the air fuel ratio of a mixture supplied to an engine in accordance with an output value of an upstream air fuel ratio sensor and a predetermined control constant thereby to make the air fuel ratio periodically oscillate in rich and lean directions, and an average air fuel ratio oscillation section that operates the control constant based on an amount of oxygen occlusion of the catalyst so that an average air fuel ratio obtained by averaging the periodically oscillating air fuel ratio is caused to oscillate in the rich and lean directions.

Abstract: In an air-fuel ratio feedback control device for a fuel injection control system, a catalyst deterioration diagnosing means for carrying out deterioration diagnosis of the catalyst is equipped with a diagnosis permission judging means for judging permission of the deterioration diagnosis of the catalyst on the basis of a driving area of the internal combustion engine, an air-fuel ratio varying means for varying the target upstream air-fuel ratio at the catalyst deterioration diagnosis time, a catalyst deterioration judging means for judging the deterioration of the catalyst on the basis of the downstream air-fuel ratio detection output at the catalyst deterioration diagnosis time, and a catalyst deterioration diagnosis prohibiting means for setting a deterioration diagnosis prohibition time of the catalyst after the catalyst deterioration diagnosis.

Abstract: An exhaust gas recirculation device (50) of an internal combustion engine (1) includes an EGR passage (51) linking an exhaust passage (6) and an intake passage (3) of the internal combustion engine, an EGR valve (54) that blocks the EGR passage when closed, an EGR catalyst (52) that is provided between a connection portion with the exhaust passage (6) in the EGR passage and an installation position of the EGR valve and that purifies an exhaust gas flowing in the EGR passage. The exhaust gas recirculation device performs exhaust gas recirculation control by which the EGR valve is opened and the exhaust gas flowing in the exhaust passage is recirculated to the intake passage via the EGR passage. The EGR catalyst is arranged in the vicinity of the connection portion (55) in the EGR passage.

Abstract: A method and device for treating exhaust gases of an internal combustion engine with a reducing agent introduced into the exhaust gases. The reducing agent is pumped out of a reactant reservoir and to a dosing valve so that after the dosing valve is opened, the reducing agent can be introduced into the engine's exhaust gas line in a dosed manner. Reducing agent can be conveyed back from the delivery device to the reservoir via a return line. The reducing agent can circulate between the delivery device and the reactant reservoir thereby, particularly when the dosing valve is closed, preventing the reactant from freezing.

Abstract: The invention concerns a system for evaluation regeneration of pollution management means (1) integrated in an exhaust line (2) of a motor vehicle engine, characterized in that it comprises means (4) for determining the thermal power input by the exhaust gas upstream of the pollution management means during the regeneration phase thereof and means (4) for comparing said power to threshold values (Sb, Sh) to determine a partial or total failure of regenerating said means.

Abstract: The exhaust gas temperature control method includes executing an exhaust gas temperature control to raise an exhaust gas temperature upon determining that a purificatory performance of an exhaust gas purification device of an engine has declined. The step of executing of the exhaust gas temperature control includes performing a first fuel injection control in which a timing of a main fuel injection is retarded and a post fuel injection is executed after the main fuel injection when the internal combustion engine is operating in the first operating region, and performing a second fuel injection control in which the timing of the main fuel injection is retarded and an execution of the post fuel injection after the main fuel injection is prohibited when the internal combustion engine is operating in the second operating region.

Abstract: An oxygen sensor for a motor vehicle having an electrode within an outer shell measures oxygen in exhaust gas exiting the vehicle and generates a signal based on the oxygen measurement. A communication device, powered by a battery or capacitor, wirelessly transmits the measured amount of oxygen from the electrode to a powertrain control module. The flow of exhaust gas through the exhaust system spins blades to spin a generator in a rotational power generation device to generate electrical current to be stored and used by the battery or capacitor. The rotational power generation device may be located in the exhaust pipe, such as through an exhaust pipe wall, and either be connected to the oxygen sensor shell or separate and connected only with electrical wires between the generator and the battery or capacitor.

Abstract: An apparatus for diagnosing deterioration of a NOx absorption-reduction catalyst provided at an exhaust path of an engine includes a sensor disposed upstream of the catalyst to sense a NOx concentration in emission gas, a calculating unit calculating a first ratio of emission of NOx to inflow of NOx or a second ratio of absorption of NOx to inflow of NOx, and a diagnosing unit which diagnoses deterioration of the catalyst using the first or second ratio as an indicator. The calculating unit calculates inflow of NOx based on an output of the sensor and either the flow volume of the emission gas or a correlation value of the flow volume of the emission gas, calculates the absorption of NOx based on the amount of rich components required for reducing the NOx, and calculates the emission of NOx based on the difference between the inflow and absorption of NOx.

Abstract: During secondary air supply control, a secondary air supply system which supplies secondary air to an upstream side of an exhaust gas control apparatus obtains a secondary air flow rate supplied to an exhaust passage provided independently for each of a plurality of cylinder groups, and detects an abnormality in the secondary air supply system based on a noxious substance amount in exhaust gas discharged from the exhaust passages which is determined from the obtained secondary air flow rates.

Abstract: An apparatus that raises temperature of a post-catalyst at an early time while suppressing reducing agent poisoning of the post-catalyst and discharge of a reducing agent into the outside when a pre-catalyst and the post-catalyst are arranged in series in an exhaust passage of an internal combustion engine in order from an upstream side thereof. The pre-catalyst is arranged to allow an exhaust gas to flow between an outer peripheral surface thereof and an inner peripheral surface of the exhaust passage. A reducing agent addition valve adding a reducing agent to allow the reducing agent to pass through the pre-catalyst is arranged immediately upstream of the pre-catalyst in the exhaust passage. Further, a retention catalyst is arranged in the exhaust passage between the pre-catalyst and the post-catalyst, to temporarily retain the reducing agent in the exhaust gas.

Abstract: A system having a particulate matter sensor in an exhaust stream of an engine upstream from a particulate filter and another such sensor downstream from the filter. There may also be an exhaust gas recirculation (EGR) control on the engine. The amount of particulate matter in or loading of the filter may be determined by the upstream filter. The working condition of the filter may be determined by the downstream sensor. The filter may have a heater and control for providing operational and particulate matter burn-off temperatures to the filter. A processor may be connected to the sensors, the EGR control and the filter heater control.

Abstract: The inventive system comprises means (10) for determining the vehicle running mode, means (11) for determining the mass of elementary carbon exhausted by the engine according said running mode, means (15) for accumulating said elementary masses during the engine operation and obtaining a total mass thereof, means (18) for calculating the volume of ash from engine lubrication oil, means (20) for calculating the volume of ash from engine feed fuel, means (21) for calculating the effective volume of the depollution means on the basis of the total volume of the means thereof as they are new or cleaned, the already calculated volume of ash and means for calculating the degree of soot loading of the depollution means on the basis of the total mass, the effective volume and the maximum density of deposits on the depollution means.

Abstract: An apparatus including an exhaust passage that forks at a separating portion and joins at a joining portion, exhaust gas purification catalysts between the separating portion and the joining portion, a filter downstream of the joining portion, reducing agent supply units supplying reducing agent to the respective exhaust passages at positions upstream of the exhaust gas purification catalysts, and control units controlling quantity of the exhaust gas passing through the exhaust gas purification catalysts. When regenerating the filter, the reducing agent is supplied by one reducing agent supply unit, and the quantity of exhaust gas passing through the exhaust gas purification catalyst provided in the exhaust passage to which the reducing agent is supplied is made smaller.

Abstract: An exhaust gas control apparatus includes a PM trapping filter provided in an exhaust gas passage of an internal combustion engine, an oxygen concentration sensor provided upstream of the filter, a device that estimates the air-fuel ratio of exhaust gas supplied to the oxygen concentration sensor, and a device that estimates the amount of PM trapped in the filter based on the estimated exhaust gas air-fuel ratio and the oxygen concentration sensor output. The amount of PM trapped in the filter is estimated using the fact that the oxygen concentration sensor output value changes according to the exhaust gas air-fuel ratio and the amount of PM accumulated on the oxygen concentration sensor. As a result, the structure of the exhaust passage is able to be kept simple because only an oxygen concentration sensor is added upstream of the filter.

Abstract: The present invention is directed to a gas particulate treatment system and may include a gas filter and a gas filter performance monitor downstream of the gas filter. The gas filter performance monitor includes a particulate trap operable to collect particulates passing through the gas filter, and a sensing apparatus associated with the gas filter performance monitor that operates to sense particulate collection in the gas filter performance monitor.

Abstract: A method for controlling a malfunction catalyst diagnostic test that determines a malfunction status of a catalyst within a selective catalytic reduction device includes monitoring an exhaust gas flow within an aftertreatment system, estimating an effect of the exhaust gas flow on an estimated reductant storage on a catalyst within the selective catalytic reduction device, and selectively disabling the malfunction catalyst diagnostic test based upon the estimating the effect of the exhaust gas flow on the estimated reductant storage.

Abstract: The invention relates to the use of a combustion fuel that differs from diesel or diesel cleavage products, in particular monoethylene glycol and/or methanol, for enriching exhaust gas in front of a particulate filter (19) of a diesel engine (11), in order to heat the exhaust gas by means of a catalytic oxidation of this combustion fuel to a temperature sufficient for a regeneration of the particulate filter (19). It also relates to the device that permits this use and to this end comprises a combustion fuel tank (25) and a combustion fuel line (27) connected to an exhaust gas train (17) of a diesel engine (11), the combustion fuel tank (25) of which is not the diesel tank (15) of the diesel engine. Furthermore, the invention can also comprise the diesel engine (11) and the tank (15) thereof, as well as the exhaust gas train (17) with the particulate filter (19).

Abstract: A device for purifying exhaust gas of an internal combustion engine comprising a NOx catalyst device, fuel feeding means for feeding additional fuel into combusted gas flowing into the NOx catalyst device during the regeneration treatment, and a NOx concentration sensor arranged on the exhaust downstream of the NOx catalyst device, wherein when the NOx concentration detected by the NOx concentration sensor is lower than a preset concentration during the regeneration treatment of this time, the amount of NOx absorbed by the NOx catalyst device during a preset period until the regeneration treatment of the next time is estimated by utilizing the NOx concentration sensor, and when the absorbed amount of NOx is smaller than a preset amount, it is decided that the amount of additional fuel fed during the regeneration processing of this time had been abnormally decreased.

Abstract: In a diagnosis apparatus for an internal combustion engine which determines the abnormality of a linear A/F sensor which is disposed on the upstream side of a catalyst of the engine and detects the A/F of exhaust gas, the apparatus includes a response/gain deterioration detection unit that separately detects the response deterioration in which the response of the linear A/F sensor is delayed and the gain deterioration in which the detection sensitivity of the linear A/F sensor is abnormal.

Abstract: An exhaust gas passageway of an internal combustion engine is basically provided with a main exhaust passageway, a bypass exhaust passageway, a bypass catalytic converter provided in the bypass exhaust passageway, a bypass control valve, an upstream air-fuel ratio sensor and a downstream air-fuel ratio sensor. The bypass exhaust passageway bypasses a portion of the main exhaust passageway between an upstream junction and a downstream junction. The bypass control valve opens or closes a portion of the main exhaust passageway. The upstream air-fuel ratio sensor is disposed upstream of the bypass catalytic converter to sense air-fuel ratio of an exhaust gas flowing into the bypass catalytic converter. The downstream air-fuel ratio sensor is disposed downstream of the bypass catalytic converter to sense air-fuel ratio of the exhaust gas flowing out of the bypass catalytic converter.

Abstract: A device for controlling the operating state of a catalytic converter in the exhaust line of an internal combustion engine, including a mechanism for determining the temperature upstream and downstream of the converter, a mechanism for injecting fuel in the exhaust line of the engine, a mechanism for calibrating a temperature model on a measured operating temperature of the catalytic converter, and a mechanism for calculating the integral of the difference between the measured temperature and the modeled temperature downstream of the converter.

Abstract: An exhaust emission purifying apparatus for an engine in which it is determined that a reducing agent supply system is clogged, which is arranged on the downstream of a pump carrying out suction and pumping of a liquid reducing agent out of a reducing agent tank, when a reduction in a pressure of the liquid reducing agent remaining in the downstream of the pump and also in the upstream of a flow control valve by an amount equal to or more than a first predetermined pressure does not occur until a cumulative injection amount obtained by sequentially integrating an injection amount of the liquid reducing agent computed in real time based on engine operating conditions reaches a predetermined amount after the pump has been temporarily stopped.

Abstract: A selective catalytic reduction (SCR) system includes a first sensor that determines a first concentration of NOx, a second sensor that determines a second concentration of NOx and NH3, and a fault determination module. The fault determination module diagnoses a fault in at least one of a dosing agent and a catalyst in an SCR device based on the first and second concentrations.

Abstract: A deterioration diagnostic system of an exhaust gas purifying catalyst includes: an upstream side switching frequency calculator calculating the number of times of switching on the upstream side; a reference value calculator calculating a downstream side rich/lean determination level having a first width; a downstream side rich/lean determination level adjuster setting the first width to a second larger width when the number of times of switching on the upstream side is smaller than a predetermined value; a downstream side switching frequency calculator calculating the number of times of switching on the downstream side; a frequency ratio calculator calculating a frequency ratio between the number of times of switching on the downstream side and the number of times of switching on the upstream side; and a deterioration determiner determining the deterioration of the exhaust gas purifying catalyst when the frequency ratio is larger than a predetermined value.

Abstract: A catalyst deterioration detector not causing false detection of catalyst deterioration by eliminating the influence of a variation of the state of the gas at the catalyst outlet on the oxygen storage amount. Setting the lean target A/F to afL1 and the rich target A/F to afR1, the maximum oxygen storage amount Cmax1 is calculated (step 106). Next, setting the lean target A/F to afL2 and the rich target A/F to afR2, the maximum oxygen storage amount Cmax2 is calculated (step 108). Lastly, setting the lean target A/F to afL3 and the rich target A/F to afR3, the maximum oxygen storage amount Cmax3 is calculated (step 110). If these all calculated maximum oxygen storage amounts Cmax1, Cmax2, Cmax3 are less than a reference value Cmaxth, catalyst deterioration is detected (step 116).

Abstract: This invention relates to a method of operating a catalyst for treating the exhaust gas of an internal combustion engine, the catalyst comprising, in addition to catalytically active noble metals, also storage components for storing hydrocarbons. During engine operating phases at low exhaust-gas temperatures, such a catalyst stores the hydrocarbons contained in the exhaust gas without burning them. When the exhaust-gas temperature rises, these hydrocarbons are desorbed again and then oxidized at the catalytically active noble metals. This process can lead to uncontrolled, vigorous combustion of the hydrocarbons stored on the catalyst and, therefore, damage to the catalyst. According to the invention, this damage is avoided by continuously calculating the respective loading of the storage components with hydrocarbons and repeatedly regenerating the storage components depending on the loading by temporarily raising the exhaust-gas temperature before damage to the catalyst can occur.

Abstract: When a nitrogen oxide storage catalyst is being regenerated, the regeneration may be terminated for example as a result of a premature load change in the engine, which can lead to incomplete emptying of the storage catalyst. The residual filling level which remains in the catalyst following an incomplete regeneration of this nature is used as the starting value for calculation of the filling level during the next storage phase. After incomplete regeneration, the nitrogen oxide conversion rate is initially greater than would be expected, on account of the residual filling level. By taking this increased conversion rate into account when calculating the filling level during the storage phase, it is possible to further improve the accuracy of the calculation.

Abstract: This disclosure relates to a method for controlling a system for regenerating a diesel particulate filter. The method includes monitoring an engine run time that has lapsed since a previous regeneration event. The method also includes monitoring backpressure behind the diesel particulate filter. The method further includes triggering a regeneration flag if the engine run time that lapsed since the previous regeneration event reaches a predetermined time limit and the backpressure exceeds a minimum value.

Abstract: A HC adsorbing material whose deterioration can be judged with high accuracy and reliability. The HC adsorbing material contains a zeolite having cation adsorption sites (Al sites) to which are bonded ions of an element (Ce+) that exhibits oxygen storage capacity (OSC) in a nonionic state (when present as an oxide).

Abstract: A control system for an internal combustion engine includes an exhaust gas purifying device, an exhaust gas temperature sensor, and temperature estimating device. The exhaust gas purifying device is provided to an exhaust duct of the internal combustion engine. The exhaust gas temperature sensor is provided in the exhaust duct on an upstream side of the exhaust gas purifying device. The temperature estimating device estimates a first exhaust gas temperature on a downstream side of the exhaust gas purifying device through a transfer function, which is expressed by a plurality of identical first-order lag elements, based on a second exhaust gas temperature on the upstream side of the exhaust gas purifying device sensed by the exhaust gas temperature sensor.

Abstract: An exhaust system for a combustion source is disclosed. The exhaust system may have a passageway connected to receive an exhaust flow from the combustion source, and a sensor disposed within the passageway. The sensor may generate a signal indicative of the concentration of a constituent in the exhaust flow. The exhaust system may also have a controller in communication with the sensor to receive the signal. The controller may be configured to selectively communicate a flow of calibration gas with the sensor during operation of the combustion source, and compare the signal received during the selective communication with a reference value. The controller may be further configured to adjust the sensor output in response to the comparison.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine including a first filter and a second filter. The first filter traps particulates in exhaust gases from said engine. The second filter is provided for failure detection and disposed downstream of the first filter. The trapping state of the second filter is detected and a filtering capability of the first filter is diagnosed based on the detect trapping state of the first filter.

Abstract: An exhaust component for use with a combustion engine is disclosed. The exhaust component may have a housing at least partially defining an inlet and an outlet, and a treatment device supported by the housing in communication with exhaust passing from the inlet to the outlet. The exhaust component may also have a life indicator permanently associated with at least one of the housing and the treatment device.

Abstract: The present invention relates to an exhaust emission control device having an NOx adsorbent, and makes it possible to judge whether the performance of the NOx adsorbent is degraded temporarily or permanently. The amounts of NOx and water adsorbed by the NOx adsorbent are measured during an actual operation of an internal combustion engine. A reference line indicating the correlation between a preselected water adsorption amount and NOx adsorption amount is then referenced to determine a reference value y0 of the NOx adsorption amount that corresponds to a measured value x1 of the water adsorption amount. Next, a measured value y1 of the NOx adsorption amount is compared against the reference value y0 to output a signal in which the result of the comparison is reflected.

Abstract: A degradation estimating apparatus for an unburned fuel component adsorption catalyst, which is connected with an internal combustion engine and has an unburned fuel component adsorbent and an oxygen storage component is provided. The apparatus includes a degradation estimating unit for making estimation for a degradation of the unburned fuel component adsorption catalyst on the basis of a first term and a second term. The first term is from the cancellation of the fuel supply to detecting a variation of an upstream side air-fuel ratio occurring due to the increase of the reductant quantity in the exhaust gas. The second term is from the cancellation of the fuel supply to detecting of a variation of the downstream side air-fuel ratio due to an increase of the reductant quantity.

Abstract: An engine control module includes an exhaust heating module, a temperature determination module, and a resistance measuring module. The exhaust heating module operates an engine at a predetermined speed to generate an exhaust gas having a predetermined temperature. The exhaust gas heats a heating element of an oxygen sensor. The temperature determination module determines, based on the predetermined speed, when the heating element is heated to the predetermined temperature. The resistance measuring module determines a resistance of the heating element when the heating element is heated to the predetermined temperature.

Abstract: A high-pressure metering pump for providing reductant in a single fluid engine exhaust dosing system having a solenoid for actuating a piston slidably received within an inner bore of a valve housing of the pump, the inner bore having a pressure chamber with an inlet check valve and an outlet check valve; and wherein movement of the piston causes high pressure reductant to be received at an atomizer of the system, the atomizer being disposed in a location to cause a maximum reduction of undesirable pollutant in the combustion gases of an engine.

Abstract: An exhaust purification device is provided to selectively perform a combustion purge control and an exhaust addition purge control in response to an operation state of the internal combustion engine. The combustion purge control process is performed in the case where a NOx occlusion amount of a NOx catalyst is larger than or equal to a first threshold value, and the exhaust addition purge control process is performed in the case where the NOx occlusion amount of the NOx catalyst is larger than or equal to a second threshold value which is larger than the first threshold value.

Abstract: A controlling method for adjusting concentrations of, for example, individual cylinder's exhaust gas constituents to provide engine functions such as catalytic converter diagnosis, increased overall catalytic converter efficiency and rapid catalyst heating, before and/or after initiating closed loop fuel injection control, using a selected temperature sensor location within a low thermal mass catalytic converter design.

Abstract: An air-fuel ratio of each cylinder is estimated on the basis of a detection value of an air-fuel ratio sensor disposed in an exhaust confluent portion. An air-fuel ratio correction quantity is computed on the basis of the estimated air-fuel ratio of each cylinder. The air-fuel ratio of an air-fuel mixture to be supplied to each cylinder is corrected on the basis of the cylinder air-fuel ratio correction quantity to reduce a variation in the air-fuel ratio between the cylinders. When a state in which the cylinder air-fuel ratio correction quantity or its learning value of any cylinder is outside a specified range continues for a while during a period in which this cylinder air-fuel ratio control is performed, a combustion is stopped for the cylinder outside the specified range and the cylinder air-fuel ratio control is continuously performed only for other normal cylinders.

Abstract: A system and an on-board-diagnosis method is provided for an exhaust aftertreatment system of an engine including a diesel particulate filter unit which encompasses a particulate filter in which soot can be oxidized by NO2 and constituents of the exhaust gas are deoxidized in a nitrogen-oxides reduction unit arranged downstream of the diesel particulate filter unit, wherein the exhaust gas flows from the diesel particulate filter unit to the nitrogen-oxides reduction unit. The on-board-diagnosis method includes estimating an NO2 content upstream of the nitrogen-oxides reduction unit, measuring at least one of an NOx or NO2 content upstream of the nitrogen-oxides reduction unit, performing a comparison between the estimated and the measured contents, and, based on the result of the comparison deciding on at least one conditioning step of the diesel particulate filter unit.

Abstract: In an internal combustion engine system having an exhaust aftertreatment system including a selective catalytic reduction (SCR) catalyst, diagnostic methods involve the intrusive perturbation of a target surface coverage parameter theta to determine the state of health of the SCR catalyst or an ammonia concentration sensor. An adaptive learning block adapts the target theta based on the use of NH3 sensing feedback from a mid-brick positioned ammonia concentration sensor to pull in system variation. A further diagnostic monitors the amount of adaptation and when the adaptive learning excessively learns, the diagnostic assumes that some system-level degradation must have occurred and the diagnostic will notify the overall emissions control monitor.

Abstract: A control device of an internal combustion engine that can accurately estimate an NOx concentration in exhaust gas by using a cylinder internal pressure as basic data. A cylinder internal pressure sensor provided to the internal combustion engine detects a cylinder internal pressure P?. An internal energy correlation value (?V·dP?/d?·??) having correlation with internal energy consumed in the cylinder is calculated based on the cylinder internal pressure P? and an in-cylinder volume V? (? represents a crank angle). The internal energy correlation value is standardized by a load ratio KL, then corrected by a function f(kl) as for a load factor KL so as to calculate an NOx concentration estimated value [NOx]={(?V·dP?/d?·??)/KL}×f(kl).

Abstract: The apparatus obtains a decreasing gradient of the maximum oxygen storing quantity Cmax with respect to the increase in an air flow rate Ga on the basis of two maximum oxygen storing quantities Cmax, which are respectively estimated in case where the air flow rate Ga assumes two different values, and the two values of the air flow rate Ga. As the deterioration degree of the catalyst unit 53 increases, the decreasing gradient increases. When the deterioration degree of the catalyst unit 53 is the same, the decreasing gradient tends to be the same, even if the degree of the response of the change in the output from a downstream air-fuel-ratio sensor 67 varies. Accordingly, the obtained decreasing gradient can be a value correctly indicating the deterioration degree of the catalyst unit 53.

Abstract: Before a large amount of PM is deposited in a filter 32, an exhaust gas cleaning system for a construction machine regenerates the filter to avoid a decrease in output due to the exhaust gas pressure rise occurring immediately before the filter is regenerated, and to reduce the likelihood of unusual increases in the internal temperature of the filter due to the combustion of the PM, associated with the execution of the regeneration, and consequential thermal damage to the filter. If a value of a differential pressure across the filter 32 is greater than a predetermined pressure, a controller 4 conducts engine speed control to a predetermined rotating speed Na suitable for the regeneration, then enters forced regeneration automatically, and burns off the PM. When the sensed differential pressure decreases below a predetermined pressure, the regeneration is terminated automatically and the engine 1 is stopped.