Abstract: An object of the invention is to suppress a reduction in accuracy of abnormality diagnosis with an abnormality diagnosis device for an exhaust gas control apparatus that performs the abnormality diagnosis regarding the exhaust gas control apparatus by using the amount of NOx flowing into an SCR catalyst as a parameter.

Abstract: In a failure diagnosis device of an emission control system that utilizes an electrode-based PM sensor provided downstream of a particulate filter in an exhaust conduit to diagnose a failure of the particulate filter, disclosed embodiments may suppress reduction of accuracy of diagnosis of a failure due to in-cylinder rich control. The failure diagnosis device of the emission control system starts application of a predetermined voltage to electrodes of the electrode-based PM sensor after a sensor recovery process that removes PM depositing between the electrodes of the PM sensor, and diagnoses a failure of the particulate filter based on an output of the PM sensor measured after elapse of a predetermined time period since the start of application of the predetermined voltage.

Abstract: An abnormality diagnosis apparatus includes an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a SCR catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; obtaining means for obtaining a NOx inflow amount into the exhaust gas purification apparatus; diagnosing means for calculating a physical quantity correlated to a NOx purification performance of the exhaust gas purification apparatus using the obtained NOx inflow amount, and diagnosing that an abnormality has occurred in the exhaust gas purification apparatus when the physical quantity is smaller than a threshold; and correcting means for, when the additive is recirculated together with a part of the exhaust gas, correcting the threshold to a smaller value than when otherwise.

Abstract: An abnormality diagnosis apparatus includes: an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a selective catalytic reduction catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; calculating means for calculating a NOx inflow amount into the exhaust gas purification apparatus using a parameter indicating an operating state of the internal combustion engine; diagnosing means for diagnosing an abnormality in the exhaust gas purification apparatus using the calculated NOx inflow amount as a parameter; and correcting means for, when a part of the exhaust gas is recirculated, increasingly correcting the calculated NOx inflow amount in accordance with an amount of the additive to be recirculated together with exhaust gas.

Abstract: Diagnostic accuracy is improved when abnormality diagnosis of a particulate filter is carried out by using a PM sensor arranged in an exhaust passage downstream of the particulate filter. An abnormality diagnostic device for a particulate filter includes a PM sensor arranged in an exhaust passage at the downstream side of the particulate filter so as to output a signal corresponding to an amount of PM deposited in between electrodes which constitute a sensor element, and a filter diagnostic unit to carry out filter diagnostic processing in which abnormality of the particulate filter is diagnosed based on an output value of the PM sensor, wherein it is decided whether to carry out the filter diagnostic processing based on a degree of variation in the output value of the PM sensor before the filter diagnostic processing is carried out.

Abstract: An exhaust gas purification apparatus for an internal combustion engine is designed to prevent a decrease in the accuracy of measurement by a PM sensor (17). The apparatus includes an NOx catalyst (7) provided in an exhaust passage (3) of an internal combustion engine (1) to reduce NOx by reducing agent supplied to it, a supplying device (6) that supplies urea to the NOx catalyst (7) from the upstream of the NOx catalyst (7), the PM sensor (17) that detects the amount of particulate matter in the exhaust gas in the downstream of the NOx catalyst (7), and a restriction part (10) that restricts supply of urea by the supplying device (6) when the amount of particulate matter adhering to the NOx catalyst (7) is equal to or larger than a threshold.

Abstract: A filter abnormality determination system includes: a PM sensor configured to introduce a part of exhaust gas flowing in the exhaust gas passage on the downstream side of a filter into a sensor body and to correlate a sensor output with an amount of particulate matter accumulated on a sensor element in the sensor body; an abnormality determining unit configured to perform filter abnormality determination on the basis of the output of the PM sensor; a determination timing determining unit configured to determine a timing at which the abnormality determining unit performs the abnormality determination on the basis of an estimated amount of particulate matter accumulated on the sensor element; and a determination performing adjusting unit configured to adjust the performing timing determined by the determination timing determining unit depending on a variation of an exhaust gas flow rate per unit time in the exhaust gas passage in which the PM sensor is disposed.

Abstract: Embodiments of the present disclosure improve the accuracy of abnormality diagnosis of a particulate filter using the output value of a PM sensor provided downstream of the particulate filter in an exhaust passage. A configuration of the invention compares a change rate of an output value of the PM sensor prior to execution of a filter diagnosis process of diagnosing an abnormality of the filter based on the output value of the PM sensor, with a reference value and determines whether a filter abnormality process is to be performed. A higher value is set to the reference value, which is to be compared with the change rate of the output value of the PM sensor, in the case where the deposition amount of PM between electrodes of the PM sensor is expected to be large, compared with the case where the deposition amount of PM is expected to be small.

Abstract: Embodiments of the present disclosure may improve the accuracy of abnormality diagnosis of a particulate filter using the output value of a particulate matter (PM) sensor provided in an exhaust passage. A time when deposition of PM between electrodes of the PM sensor is restarted after completion of a sensor recovery process may be specified as a PM deposition restart time. A process of diagnosing an abnormality of a filter based on the output value of the PM sensor at a first determination time after the PM deposition restart time may be specified as a filter diagnosis process. To determine, whether the filter diagnosis process is to be performed, a change rate of the output value of the PM sensor in a time period from the PM deposition restart time to a predetermined second determination time before the first determination time, may be compared with a threshold value.

Abstract: In a failure diagnosis device of an emission control system that utilizes an electrode-based PM sensor provided downstream of a particulate filter in an exhaust conduit to diagnose a failure of the particulate filter, disclosed embodiments may suppress reduction of accuracy of diagnosis of a failure due to in-cylinder rich control. The failure diagnosis device of the emission control system starts application of a predetermined voltage to electrodes of the electrode-based PM sensor after a sensor recovery process that removes PM depositing between the electrodes of the PM sensor, and diagnoses a failure of the particulate filter based on an output of the PM sensor measured after elapse of a predetermined time period since the start of application of the predetermined voltage.

Abstract: In a failure diagnosis device of an emission control system that utilizes an electrode-based PM sensor to diagnose a failure of a particulate filter, some embodiments may be to suppress reduction of accuracy of diagnosis of a failure due to in-cylinder rich control. The failure diagnosis device of the emission control system performs a measurement process. The measurement process includes a sensor recovery process of removing PM depositing between the electrodes of the electrode-based PM sensor, a process of starting application of the predetermined voltage to the electrodes of the PM sensor after completion of the sensor recovery process, and a process of obtaining an output value of the PM sensor after elapse of a predetermined time period since the start of application of the predetermined voltage to the electrodes of the PM sensor.

Abstract: An exhaust gas purification apparatus including a filter, an NOx selective reduction catalyst at the downstream side of the filter, a supply device for supplying a reducing agent to the NOx selective reduction catalyst, and a PM sensor for detecting an amount of particulate matter in an exhaust gas at the downstream side of the NOx selective reduction catalyst. A supply decrease part makes an amount of supply of the reducing agent smaller in cases where at least one of several conditions is satisfied.

Abstract: An object of the present invention is to increase the accuracy of a deterioration determination in a deterioration determination system of an exhaust emission control device having a selective reduction type NOx catalyst, by suppressing false determinations when the deterioration determination is made. The deterioration determination system includes a catalyst having an oxidative capacity downstream of a NOx catalyst using ammonia as a reducing agent. When an amount of ammonia adsorbed by the NOx catalyst is larger than an equilibrium adsorption amount, out of the amount of ammonia flowing into the catalyst having the oxidative capacity, at least one of the amount of ammonia flowing out from the catalyst having the oxidative capacity and the amount of ammonia converted to NOx in the catalyst having the oxidative capacity or a total value of both is calculated.

Abstract: A function diagnostic system for a filter of an internal combustion engine may be provided. The function diagnostic system may include a PM sensor and an electronic control unit. The electronic control unit may be configured to: calculate a NOx conversion rate in the filter; determine whether a NOx converting function of the filter is normal; execute a sensor regeneration process for removing the PM deposited between an electrodes of the PM sensor; continuously monitor an output value of the PM sensor after a predetermined PM deposition restart time, after execution of the sensor regeneration process is finished; and determine that there is an abnormality in a PM trapping function of the filter, when the output vale of the PM sensor, which has been continuously monitored, is reduced when the electronic control unit determines that the NOx converting function of the filter is in a normal status.

Abstract: An abnormality diagnosis apparatus includes an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a SCR catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; obtaining means for obtaining a NOx inflow amount into the exhaust gas purification apparatus; diagnosing means for calculating a physical quantity correlated to a NOx purification performance of the exhaust gas purification apparatus using the obtained NOx inflow amount, and diagnosing that an abnormality has occurred in the exhaust gas purification apparatus when the physical quantity is smaller than a threshold; and correcting means for, when the additive is recirculated together with a part of the exhaust gas, correcting the threshold to a smaller value than when otherwise.

Abstract: An abnormality diagnosis apparatus includes: an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a selective catalytic reduction catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; calculating means for calculating a NOx inflow amount into the exhaust gas purification apparatus using a parameter indicating an operating state of the internal combustion engine; diagnosing means for diagnosing an abnormality in the exhaust gas purification apparatus using the calculated NOx inflow amount as a parameter; and correcting means for, when a part of the exhaust gas is recirculated, increasingly correcting the calculated NOx inflow amount in accordance with an amount of the additive to be recirculated together with exhaust gas.

Abstract: An object of the invention is to suppress a reduction in accuracy of abnormality diagnosis with an abnormality diagnosis device for an exhaust gas control apparatus that performs the abnormality diagnosis regarding the exhaust gas control apparatus by using the amount of NOx flowing into an SCR catalyst as a parameter.

Abstract: Diagnostic accuracy is improved when abnormality diagnosis of a particulate filter is carried out by using a PM sensor arranged in an exhaust passage downstream of the particulate filter. An abnormality diagnostic device for a particulate filter includes a PM sensor arranged in an exhaust passage at the downstream side of the particulate filter so as to output a signal corresponding to an amount of PM deposited in between electrodes which constitute a sensor element, and a filter diagnostic unit to carry out filter diagnostic processing in which abnormality of the particulate filter is diagnosed based on an output value of the PM sensor, wherein it is decided whether to carry out the filter diagnostic processing based on a degree of variation in the output value of the PM sensor before the filter diagnostic processing is carried out.

Abstract: In a failure determination system that performs failure determination of an exhaust gas purification apparatus having a NOx selective catalytic reduction catalyst (NOx catalyst) that is disposed in an exhaust passage of an internal combustion engine and uses ammonia as a reducing agent, the failure determination of the exhaust gas purification apparatus is performed by a failure determination unit, based on a detected value of a NOx sensor that detects NOx in exhaust gas. Then, based on an adsorption amount difference at assumed failure that is the difference between an ammonia equilibrium adsorption amount in the NOx catalyst in an equilibrium state of ammonia adsorption, assuming that the exhaust gas purification apparatus is in a predefined failure state, and an actual ammonia adsorption amount in the NOx catalyst, the failure determination itself by the failure determination unit is inhibited or the use of the NOx sensor in the failure determination is restricted.

Abstract: A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. To this end, provision is made for an NOx selective reduction catalyst arranged in an exhaust passage of the internal combustion engine to reduce NOx by means of a reducing agent supplied thereto, a supply device to supply urea water as the reducing agent from an upstream side of the NOx selective reduction catalyst, a PM sensor to detect an amount of particulate matter in an exhaust gas at the downstream side of the NOx selective reduction catalyst, and a control unit to make an amount of production of intermediate products from the urea water supplied from the supply device to ammonia smaller when an amount of particulate matter is detected by the PM sensor than when not detected.