Abstract:
A controller to diagnose a selective catalytic reduction (SCR) system of an aftertreatment system executes computer-readable instructions to determine a first NOx value at an outlet of the SCR system, determine an ammonia (NH3) slip value based at least in part on the first NOx value, determine a second NOx value of a healthy SCR model, determine a third NOx value of a degraded SCR model, compute at least one degradation factor based on the ammonia slip, the first NOx value, the second NOx value, and the third NOx value, and diagnose a normal operation or an abnormal operation of the SCR system based on the at least one degradation factor.
Abstract:
A system includes a processing circuit having a memory coupled to one or more processors, the memory storing instructions therein that, when executed by the one or more processors, cause the one or more processors to: receive engine operational data, the engine operational data indicative of at least one engine operational condition; determine, based on the engine operational data, an estimated exhaust temperature; generate, based on the estimated exhaust temperature and a finite time horizon, a forecasted exhaust temperature; correct the forecasted exhaust temperature based on a downpipe model to generate a first inlet temperature profile corresponding to a first component of the exhaust aftertreatment system; and generate, based on the first inlet temperature profile, a second inlet temperature profile corresponding to a second component of the exhaust aftertreatment system.
Abstract:
A method is provided for monitoring an emission device coupled to an engine. In one example approach, the method comprises: following a deceleration fuel shut-off duration, indicating degradation of the emission device based on an amount of rich products required to cause a sensor to become richer than a threshold. The amount of rich products required may be correlated to an amount of oxygen stored in the emission device.
Abstract:
A method for operating a dosing device for metering an additive to an exhaust-gas treatment device includes determining a dosing amount of additive required by the exhaust-gas treatment device in step a). Subsequently, in step b), an operating mode for the dosing device is determined by carrying out at least steps b.1) and b.2). In step b.1), at least one characteristic operating value of at least one component of the dosing device is provided being definitive of a degree of aging of the dosing device. In step b.2), an operating mode for the dosing device is set in dependence on the characteristic operating value from step b.1). In step c), the dosing device is operated with the set operating mode so that the dosing amount required in step a) is supplied to the exhaust-gas treatment device. A motor vehicle having a dosing device is also provided.
Abstract:
Various systems and methods are described for detecting ammonia slip. In one example method, an exhaust system with two NOx sensors uses transient responses of the NOx sensors to allocate tailpipe NOx sensor output to NOx and NH3 levels therein. An ammonia slip detection counter with gains is included that determines a probability of NOx and NH3 based on the measured sensor activities that are further processed by a controller to adjust one or more parameters based on the allocation and changes of sensor output.
Abstract:
A method is provided for monitoring an emission device coupled to an engine. In one example approach, the method comprises: following a deceleration fuel shut-off duration, indicating degradation of the emission device based on an amount of rich products required to cause a sensor to become richer than a threshold. The amount of rich products required may be correlated to an amount of oxygen stored in the emission device.
Abstract:
A method for operating a dosing device for metering an additive to an exhaust-gas treatment device includes determining a dosing amount of additive required by the exhaust-gas treatment device in step a). Subsequently, in step b), an operating mode for the dosing device is determined by carrying out at least steps b.1) and b.2). In step b.1), at least one characteristic operating value of at least one component of the dosing device is provided being definitive of a degree of aging of the dosing device. In step b.2), an operating mode for the dosing device is set in dependence on the characteristic operating value from step b.1). In step c), the dosing device is operated with the set operating mode so that the dosing amount required in step a) is supplied to the exhaust-gas treatment device. A motor vehicle having a dosing device is also provided.
Abstract:
Various methods for and embodiments of an aftertreatment system which includes a catalyst disposed upstream of a particulate filter are provided. In one example, the method includes, conducting soot regeneration of the particulate filter under a selected operating condition, and determining whether a soot regeneration frequency of the particulate filter is greater than a threshold frequency. The method further includes initiating a sulfur regeneration of the aftertreatment system based on the soot regeneration frequency of the particulate filter being greater than the threshold frequency, determining whether the soot regeneration frequency of the particulate filter is less than the threshold frequency after the sulfur regeneration, and conducting non-regeneration operation of the aftertreatment system based on the soot regeneration frequency of the particulate filter being less than the threshold frequency after the sulfur regeneration of the aftertreatment system.
Abstract:
A particulate filter (PF) ash loading prediction method includes the steps of: regenerating the PF using a first soot loading prediction model or a second soot loading prediction model; determining whether the regeneration of the PF was initiated by the first soot loading prediction model or the second soot loading prediction model; incrementing a first counter associated with the first soot loading prediction model or a second counter associated with the second soot loading prediction model, dependent on the determining step; comparing a ratio of the first counter and the second counter; and establishing whether the PF requires servicing, dependent on the ratio.
Abstract:
A selective catalytic reduction thawing control system that can distinguish between a thawing failure and a malfunction and can prevent a malfunction of a supply module (“SM”) pump. The thawing control system includes a thawing control unit that detects a pressure inside the supply module when the SM pump is operated, and stops the operation of the SM pump and continues thawing of urea water when the pressure is less than a predetermined value.