Abstract:
A method of increasing a weighting factor of an exponentially weighted moving averaging (“EWMA”) filter is provided. The method includes monitoring a data stream containing raw data values, and determining an EWMA value based on the data stream by an electronic control module. The method includes determining if the EWMA value is between a predetermined maximum fault threshold value and a predetermined minimum fault threshold value. The method includes increasing the weighting factor of the EWMA filter to more heavily weigh incoming raw data values of the data stream based on the difference between the first raw data value and a previously calculated filtered value exceeding the calibration value.
Abstract:
A method of estimating a mass flow rate of nitrogen oxides in exhaust gas includes sensing a mass flow rate of a flow of exhaust gas from the engine. A nitrogen oxides base concentration for when the engine is operating at a reference state is defined, and a nitrogen oxides ratio for a current operating state of the internal combustion engine is calculated. The mass flow rate of the flow of exhaust gas, the nitrogen oxides base concentration, and the nitrogen oxides ratio for the current operating state of the engine are multiplied together to define an estimated value of the current mass flow rate of nitrogen oxides in the flow of exhaust gas from the engine. The estimated value of the mass flow rate of nitrogen oxides may be compared to the output from a nitrogen oxides sensor to determine proper functionality of the nitrogen oxides sensor.
Abstract:
A dosing control system for an exhaust system includes: a reductant fluid tank operable to contain a reductant solution comprising urea; an injector disposed in operable communication between a reductant tank and an SCR apparatus, the injector being operable to inject the reductant solution from the reductant tank into a flow of exhaust upstream of the SCR apparatus; a urea quality sensor (UQS) configured and disposed to sense a concentration of the urea in the reductant solution; and, a control module disposed in signal communication with the UQS and in operable communication with the injector, the control module being operable to adjust a dosing of the reductant solution injected by the injector based on a concentration of the urea in the reductant solution.
Abstract:
A dosing control system for an exhaust system of an engine includes: a tank containing a reductant solution having urea; an injector operable to inject the reductant solution into an exhaust flow upstream of an SCR apparatus; first and second NOx sensors disposed to sense NOx emissions in the exhaust flow upstream and downstream, respectively, of the SCR apparatus; and a control module. The control module is disposed in signal communication with the first and second NOx sensors and in operable communication with the injector, the control module being operable to set an original dosing level and decrease a dosing of the reductant solution injected by the injector based on a determination from signals received from the first and second NOx sensors that a reduction in a conversion efficiency of the SCR apparatus below a defined level of conversion efficiency has occurred.
Abstract:
A method for diagnosing an Oxidation Catalyst (OC) device of an exhaust gas treatment system is provided. The method monitors a differential temperature across the OC device. The method determines whether the differential temperature reveals a temperature spike. The method determines that the OC device operates properly in response to determining that the differential temperature reveals a temperature spike.
Abstract:
A method is disclosed for regulating an exhaust after-treatment (AT) system having a diesel particulate filter (DPF) in fluid communication with a diesel engine. The method includes detecting operation of the diesel engine during which the engine generates a flow rate of particulate matter (PM) directed into the DPF. The method also includes detecting a flow rate of PM exiting the DPF in response to the flow rate of PM directed into the DPF. The method additionally includes tracking the detected flow rate alongside a predicted PM flow rate for monitoring and comparison thereof. The method also includes pausing in time the tracking of the predicted flow rate, if the detected flow rate has experienced a decline. Furthermore, the method includes resuming tracking the predicted flow rate when the detected flow rate returns to a value before the decline and using such value to regulate operation of the AT system.
Abstract:
A method of estimating a mass flow rate of nitrogen oxides in exhaust gas includes sensing a mass flow rate of a flow of exhaust gas from the engine. A nitrogen oxides base concentration for when the engine is operating at a reference state is defined, and a nitrogen oxides ratio for a current operating state of the internal combustion engine is calculated. The mass flow rate of the flow of exhaust gas, the nitrogen oxides base concentration, and the nitrogen oxides ratio for the current operating state of the engine are multiplied together to define an estimated value of the current mass flow rate of nitrogen oxides in the flow of exhaust gas from the engine. The estimated value of the mass flow rate of nitrogen oxides may be compared to the output from a nitrogen oxides sensor to determine proper functionality of the nitrogen oxides sensor.
Abstract:
A method for particulate filter performance monitoring in an exhaust gas treatment system is provided. The method includes monitoring a current received from a soot sensor in the exhaust gas treatment system and comparing the current to a soot sensor current threshold. Based on determining that the current is greater than or equal to the soot sensor current threshold, an accumulated engine out soot value is compared to an accumulated engine out soot threshold. A particulate filter fault is set based on determining that the accumulated engine out soot value is less than the accumulated engine out soot threshold. A monitoring system and an exhaust gas treatment system of an engine are also provided.
Abstract:
A dosing control system for an exhaust system includes: a reductant fluid tank operable to contain a reductant solution comprising urea; an injector disposed in operable communication between a reductant tank and an SCR apparatus, the injector being operable to inject the reductant solution from the reductant tank into a flow of exhaust upstream of the SCR apparatus; a urea quality sensor (UQS) configured and disposed to sense a concentration of the urea in the reductant solution; and, a control module disposed in signal communication with the UQS and in operable communication with the injector, the control module being operable to adjust a dosing of the reductant solution injected by the injector based on a concentration of the urea in the reductant solution.
Abstract:
A monitoring system for a single can oxidation catalyst (OC)/particulate filter (PF) member includes a controller including a first temperature sensor input configured to receive a first exhaust temperature upstream of an OC portion of the single can OC/PF member, a second temperature sensor input configured to receive a second exhaust temperature downstream of the first temperature. The controller is configured and disposed to calculate an exothermic capacity of the OC portion and determine washcoat deterioration of a PF portion of the single can OC/PF member based on the exothermic capacity of the OC portion.