A filtration assembly for removing particulate matter from exhaust gas produced by an engine, including: a first filter; a second filter positioned downstream of the first filter; and a valve including: a first ring defining a plurality of first openings, and a second ring defining a plurality of second openings, the second ring abutting the first ring. The valve is moveable between a closed position in which the plurality of first openings are misaligned with the plurality of second openings to prevent a fluid from flowing through the plurality of first and second openings, and an open position in which the second ring is rotated relative to the first ring such that the plurality of first openings are aligned with the plurality of second openings allowing the fluid to flow therethrough. A first end of the valve is positioned at an outlet of the first filter, and a second end of the valve is positioned at an inlet of the second filter. In the closed position of the valve, substantially all of the exhaust gas flows through the second filter, and in the open position of the valve, at least a portion of the exhaust gas flows through the valve and bypasses the second filter.

A fine particle detector includes: a casing part configured to accommodate an object to be heated; an electromagnetic wave generating part configured to generate electromagnetic waves of different frequencies; at least one power sensor configured to measure powers, from the casing part, of the electromagnetic waves that have entered into the casing part; and a fine particle detection controlling part configured to determine, based on the powers of the electromagnetic waves of the different frequencies measured by the at least one power sensor, whether an accumulated amount of fine particles accumulated in the object to be heated is greater than or equal to a predetermined accumulated amount.

A method includes calculating whether a quantity of the PMs accumulated in a PF is at or above a risk level at which damage to the PF is caused when reproducing the PF, calculating a driving condition index by accumulating a weighting factor for a driving condition under which there is a likelihood of causing the damage to the PF, when the amount of accumulated PMs is at or above the risk level; calculating a temperature index in accordance with a temperature of the PF and a PM index in accordance with the quantity of the accumulated PMs when the quantity of the accumulated PMs is at or above the risk level; calculating a degradation condition index considering the driving condition index, the temperature of the PF, and the quantity of accumulated PMs; and changing a reproduction periodicity of the PF according to the degradation condition index.

Defect detection systems include at least one nozzle for delivering a CO.sub.2 particulate fluid to an inlet end of a plugged honeycomb body. Defects in the honeycomb, if any, are determined by monitoring CO.sub.2 particulate flow at the outlet end of the honeycomb body. Methods for detecting defects in plugged honeycomb bodies are also disclosed.

The invention relates to a method for determining a loading of a soot filter with soot particles from an exhaust gas mass flow of an internal combustion engine in a motor vehicle, a control device for an internal combustion engine having a soot filter, and a computer program product for carrying out the method. In the first step 100 of the method a characteristic curve for the relationship between the exhaust gas mass flow, exhaust gas temperature, ambient pressure, and pressure drop across the soot filter without loading is determined; in the second step 200 a second exhaust gas mass flow and a second pressure drop that occurs during loading of the soot filter are determined; in the third step 300, from the characteristic curve the first pressure drop is determined for which the first and second exhaust gas mass flows have the same value; in the fourth step 400 an estimated value for the loading of the soot filter is computed via a real-time parameter estimation, preferably by use of the gradient method, based on the previously determined parameters. The method allows a reliable determination of the instantaneous loading of a particulate filter, regardless of the type of measuring signals used in each case for characterizing the loading behavior of the soot filter.

Upon a predetermined first diagnosis execution condition being met, an electronic control unit executes a first diagnosis process of diagnosing whether an exhaust gas recirculation device has an abnormality based on an amount of change that a measured value of an intake air pressure undergoes as a result of a change in an EGR valve position. When a predetermined second diagnosis execution condition is met and, moreover, the first diagnosis process is not being executed, the electronic control unit executes a second diagnosis process of diagnosing whether an exhaust gas cleaning filter has a fracture based on measured values of an incoming gas temperature and an outgoing gas temperature.

A method for predicting soot build-up in an engine system when operating according to an intended drive cycle. The engine system includes an internal combustion engine and an exhaust gas aftertreatment system provided with a particulate filter. The method includes providing data representing engine operational conditions for the internal combustion engine during the intended drive cycle, wherein the data comprises values for at least engine speed and engine torque distributed over a time period representing the intended drive cycle; determining a working temperature for the exhaust gas aftertreatment system during the intended drive cycle based on the data representing the engine operational conditions; providing a reference relation between working temperature of the exhaust gas aftertreatment system and a corresponding estimated magnitude of a build-up of soot in the exhaust gas aftertreatment system; and predicting soot build-up in the engine system when operating according to the intended drive cycle by comparing the determined working temperature for the exhaust gas aftertreatment system with the reference relation.

A maintenance system includes a processing circuit that executes a calculation process for calculating recommended execution time of a regeneration process. The processing circuit of the maintenance system also executes a display process for displaying the calculated recommended execution time. The processing circuit executes an analysis process for analyzing a usage mode of a vehicle based on history information of travel data. The processing circuit refers to an analysis result of the analysis process in the calculation process. When the analysis result of the analysis process indicates a usage mode in which overaccumulation is unlikely to recur, the processing circuit calculates the recommended execution time shorter than when the analysis result does not indicate the usage mode in which the overaccumulation is unlikely to recur.

A method for detecting a replacement of a differential pressure sensor arranged for measuring a differential pressure across a filter of an aftertreatment system of a vehicle. The method includes determining a sensor offset value being an offset from a sensor value measured with a differential pressure sensor; adding an adaption value to the measured sensor value to compensate for the offset value to centre the sensor value around a predetermined level; if a sum of a subsequently measured sensor value and the adaption value exceeds a limit value, concluding that the differential pressure sensor has been replaced.

Apparatus and methods are disclosed which apply inorganic particles to a plugged honeycomb body comprising porous walls, an inlet end and an outlet end. The apparatus comprises a particle counter and the method comprises counting a selected portion of the inorganic particles from a first sampling port upstream from the plugged honeycomb body and a second sampling port downstream from the plugged honeycomb body. The selected portion of the inorganic particles are in a preselected inorganic particle size range. Filtration efficiency can be determined while inorganic particles are being deposited, for example to increase filtration efficiency,