Abstract: A method of controlling an exhaust system for a diesel engine comprises providing an aftertreatment system comprising a first catalyst and a diesel exhaust fluid injection system, determining a preliminary dose of a diesel exhaust fluid of the diesel exhaust fluid injection system based on an incoming exhaust gas flow and an exhaust gas temperature, determining an NH3 factor based on incoming exhaust gas oxygen concentration and the incoming exhaust gas flow temperature, and determining a final dose of diesel exhaust fluid by multiplying the preliminary dose of diesel exhaust fluid by the NH3 factor.

Abstract: Selective catalytic reaction (SCR) failure detection systems and methods for propulsion systems. The method includes obtaining (a) an upstream (of the SCR unit) NOx concentration value, and (b) a downstream NOx concentration value, and caching (a) and (b). The obtaining and caching is repeated until N cached values are obtained, where N is a preprogrammed number. Using the N cached values, an upstream average of NOx, an upstream standard deviation, a downstream average of NOx, and a downstream standard deviation are calculated. The calculated values are input for a failure detection algorithm pertaining to nitrogen oxides (NOx) that generates a linear correlation factor. A best performing unacceptable (BPU) part is detected when the linear correlation factor is greater than a preprogrammed fail threshold.

Abstract: A method of controlling an exhaust system for a diesel engine comprises providing an aftertreatment system comprising a first catalyst and a diesel exhaust fluid injection system, determining a preliminary dose of a diesel exhaust fluid of the diesel exhaust fluid injection system based on an incoming exhaust gas flow and an exhaust gas temperature, determining an NH3 factor based on incoming exhaust gas oxygen concentration and the incoming exhaust gas flow temperature, and determining a final dose of diesel exhaust fluid by multiplying the preliminary dose of diesel exhaust fluid by the NH3 factor.

Abstract: Systems and associated methods of treating diesel exhaust in a vehicle are disclosed. An example method includes providing an exhaust aftertreatment device in an exhaust tailpipe, and a first nitrogen oxide (NOx) sensor upstream of the exhaust aftertreatment device, with the exhaust aftertreatment device configured to reduce NOx present in an exhaust flow through the exhaust aftertreatment device with a treatment fluid applied to the exhaust flow. This example method may also include measuring a concentration of NOx in the exhaust flow with the first sensor, determining an error in the measurement of the NOx concentration, and applying a learning corrective adjustment in a subsequent measurement of the NOx concentration in the exhaust flow in response to that determination. A first magnitude of the learning corrective adjustment may be based at least in part upon a second magnitude of the error in the measurement.

Abstract: A method of adjusting reductant injection for a selective catalyst reduction device with a soot filter (SCRF) includes calculating, through a processor, an amount of soot in the SCRF, determining, through the processor, a shrinking core model of the SCRF based on the amount of soot, calculating, with the processor using the shrinking core model, an amount of reductant to inject into the SCRF, and injecting the amount of reductant into the SCRF.

Abstract: A method of operating an internal combustion engine of a vehicle is provided to maintain cylinder balance. A first operating mode corresponding to a steady state operation of the internal combustion engine is differentiated from a second operating mode corresponding to a transient operation of the internal combustion engine based upon a first operating parameter of the internal combustion engine. In the first operating mode, a first control strategy provides cylinder balance. In the second operating mode, a second control strategy, different than the first control strategy, provides cylinder balance. The second control strategy utilizes a dynamic factor based upon a second operating parameter of the internal combustion engine.

Abstract: A method for treating exhaust gas from an internal combustion engine including, determining if a steady state condition exist and perturbing a reductant injection corresponding the steady state. Measuring a first and a second NOx values corresponding to the steady state and resulting from the perturbation, and computing a gradient of the NOx values relative to the steady state respectively. The method also includes comparing the gradient of the second NOx value with one of the first NOx value, if the gradient of the first NOx value is within a selected range of the gradient of the second NOx value, identifying poor efficiency operation for the engine and setting an estimated reductant storage at zero. Otherwise if the gradient of the second NOx value exceeds a selected threshold, identifying a reductant slip condition and setting the estimated storage at maximum, if not, making no corrections in estimated storage.

Abstract: Described herein is a method for detecting steady state ammonia slip for a motor vehicle having an internal combustion engine and an emissions control system. The emissions control system includes a selective catalytic reduction (SCR) device, a NOx sensor, and a controller. The controller executes a method for ammonia slip detection that includes determining if the SCR device is at steady state, comparing a NOx measurement from the NOx sensor with a predicted NOx value. If the NOx measurement exceeds the predicted NOx value by a threshold, perturbing a reductant injection, the perturbation having a selected magnitude and a selected duration. The method also includes measuring a NOx value resulting from the perturbation and computing a gradient thereof relative to the measured NOx, and ascertaining if a gradient of the NOx resulting from the perturbation exceeds a threshold and identifying a reductant slip condition if so.

Abstract: A method of operating an internal combustion engine of a vehicle is provided to maintain cylinder balance. A first operating mode corresponding to a steady state operation of the internal combustion engine is differentiated from a second operating mode corresponding to a transient operation of the internal combustion engine based upon a first operating parameter of the internal combustion engine. In the first operating mode, a first control strategy provides cylinder balance. In the second operating mode, a second control strategy, different than the first control strategy, provides cylinder balance. The second control strategy utilizes a dynamic factor based upon a second operating parameter of the internal combustion engine.

Abstract: A method for treating exhaust gas from an internal combustion engine including, determining if a steady state condition exist and perturbing a reductant injection corresponding the steady state. Measuring a first and a second NOx values corresponding to the steady state and resulting from the perturbation, and computing a gradient of the NOx values relative to the steady state respectively. The method also includes comparing the gradient of the second NOx value with one of the first NOx value, if the gradient of the first NOx value is within a selected range of the gradient of the second NOx value, identifying poor efficiency operation for the engine and setting an estimated reductant storage at zero. Otherwise if the gradient of the second NOx value exceeds a selected threshold, identifying a reductant slip condition and setting the estimated storage at maximum, if not, making no corrections in estimated storage.

Abstract: Described herein is a method for detecting steady state ammonia slip for a motor vehicle having an internal combustion engine and an emissions control system. The emissions control system includes a selective catalytic reduction (SCR) device, a NOx sensor, and a controller. The controller executes a method for ammonia slip detection that includes determining if the SCR device is at steady state, comparing a NOx measurement from the NOx sensor with a predicted NOx value. If the NOx measurement exceeds the predicted NOx value by a threshold, perturbing a reductant injection, the perturbation having a selected magnitude and a selected duration. The method also includes measuring a NOx value resulting from the perturbation and computing a gradient thereof relative to the measured NOx, and ascertaining if a gradient of the NOx resulting from the perturbation exceeds a threshold and identifying a reductant slip condition if so.

Abstract: A method of adjusting reductant injection for a selective catalyst reduction device with a soot filter (SCRF) includes calculating, through a processor, an amount of soot in the SCRF, determining, through the processor, a shrinking core model of the SCRF based on the amount of soot, calculating, with the processor using the shrinking core model, an amount of reductant to inject into the SCRF, and injecting the amount of reductant into the SCRF.

Abstract: An exhaust aftertreatment system includes first and second selective catalytic reduction devices (SCRs) and a single reductant injection system. A total ammonia storage capacity and an ammonia storage level are determined for the first and second SCRs, and determine a total SCR ammonia storage level for the first and second SCRs based upon the ammonia storage level on the first and second SCRs. A first storage error is determined, and a second storage error is determined based upon an ammonia storage level and an ammonia storage capacity for the second SCR. A second reductant dosing rate is determined based upon the second storage error. The reductant injection system injects reductant into the exhaust gas feedstream based upon the second reductant dosing rate when the second storage error indicates an imbalance between the ammonia storage on the first SCR and the ammonia storage on the second SCR.

Abstract: An exhaust aftertreatment system includes first and second selective catalytic reduction devices (SCRs) and a single reductant injection system. A total ammonia storage capacity and an ammonia storage level are determined for the first and second SCRs, and determine a total SCR ammonia storage level for the first and second SCRs based upon the ammonia storage level on the first and second SCRs. A first storage error is determined, and a second storage error is determined based upon an ammonia storage level and an ammonia storage capacity for the second SCR. A second reductant dosing rate is determined based upon the second storage error. The reductant injection system injects reductant into the exhaust gas feedstream based upon the second reductant dosing rate when the second storage error indicates an imbalance between the ammonia storage on the first SCR and the ammonia storage on the second SCR.

Abstract: A method of operating an internal combustion engine, and more particularly a fuel injector is disclosed. The fuel injector is commanded to inject a fuel requested quantity. The fuel requested quantity is adjusted by closed-loop for controlling an engine speed to match a target value thereof. A value of a first parameter indicative of an amount of electrical energy supplied to an electric battery by an electric generator coupled to the internal combustion engine is measured. A value of a voltage generated by the electric battery and a value of the engine speed are measured. A reference value of the fuel requested quantity is calculated on the basis of the voltage value, the engine speed value and the value of the first parameter. A difference between the value of the adjusted fuel requested quantity and the reference value is calculated and used to control the internal combustion engine.

Abstract: A control apparatus is disclosed for operating a fuel injector of an internal combustion engine. The control apparatus includes an Electronic Control Unit configured to: perform a first calculation task in order to calculate a set of Start Of Injection values (SOIi) of a train of injections, calculate an angular position (DIAngPos) of the crankshaft defining the start of a second calculation task, and perform the second calculation task in order to calculate a set of values (ETi) of the energizing time of the injections of the train. The angular position (DIAngPos) is calculated as a function of the Start Of Injection value (FirstSOI) of the first injection of the train as calculated by the first calculation task.

Abstract: A method of operating an internal combustion engine, and more particularly a fuel injector is disclosed. The fuel injector is commanded to inject a fuel requested quantity. The fuel requested quantity is adjusted by closed-loop for controlling an engine speed to match a target value thereof. A value of a first parameter indicative of an amount of electrical energy supplied to an electric battery by an electric generator coupled to the internal combustion engine is measured. A value of a voltage generated by the electric battery and a value of the engine speed are measured. A reference value of the fuel requested quantity is calculated on the basis of the voltage value, the engine speed value and the value of the first parameter. A difference between the value of the adjusted fuel requested quantity and the reference value is calculated and used to control the internal combustion engine.

Abstract: A method of estimating an injection pressure for an internal combustion engine of an automotive system is disclosed that is well-suited for use with a digital pressure sensor, which periodically acquires injection pressure signals. An updated injection pressure value is calculated starting from an injection pressure signal and compensated with a pressure-correcting parameter, based on an elapsed time from the injection pressure signal acquisition, an actual engine speed and an actual fuel injection quantity.

Abstract: A method and apparatus for identifying a faulty fuel injector is disclosed. The fuel injectors are commanded in sequence to inject a fuel quantity. A plurality of values of a crankshaft rotational speed is measured during the combustion of the injected the quantities. The measured values are processed to calculate a respective unbalancing value representative of the fuel quantity injected by the fuel injector. An average value of the calculated unbalancing values is calculated and subtracted from each of the unbalancing values to obtain a respective adjusted unbalancing value. The standard deviation of the adjusted unbalancing values is calculated and multiplied with each of the adjusted unbalancing values to obtain a respective corrected unbalancing value. The corrected unbalancing values are compared with a predetermined threshold value thereof, and a faulty fuel injector is identified if the corresponding corrected unbalancing value exceeds the predetermined threshold value.

Abstract: A control apparatus is disclosed for operating a fuel injector of an internal combustion engine. The control apparatus includes an Electronic Control Unit configured to: perform a first calculation task in order to calculate a set of Start Of Injection values (SOIi) of a train of injections, calculate an angular position (DIAngPos) of the crankshaft defining the start of a second calculation task, and perform the second calculation task in order to calculate a set of values (ETi) of the energizing time of the injections of the train. The angular position (DIAngPos) is calculated as a function of the Start Of Injection value (FirstSOI) of the first injection of the train as calculated by the first calculation task.