A method for modelling engine emissions output is provided. The method includes determining a stoichiometric engine output emission value based on a dynamic data-based model and parameters associated with at least one engine operating state, wherein the at least one engine operating state is calculated at a substantially stoichiometric air-fuel ratio, selecting a target air-fuel ratio based on the at least one engine operating state and a desired engine performance, applying a predetermined static model to determine a correction factor to the stoichiometric engine output emission value, based on the target air-fuel ratio, and applying the correction factor to the determined stoichiometric engine output emission value to yield an air-fuel-ratio-corrected emission output value.

The invention relates to a method for determining pollutant emissions from a vehicle (PSEE, pollutant emissions from the post-treatment system), said method being based on the use of measurements of the position (pos.sub.GPS) and/or the altitude (alt.sub.GPS) and/or the speed of the vehicle (v.sub.GPS), using models of the vehicle (MOD VEH), the engine (MOD MOT) and the post-treatment system (MOD POT) produced with macroscopic parameters (PAR).

A system includes an aftertreatment system configured to treat emissions from an engine via a catalyst and a controller. The controller is configured to obtain one or more engine signals representative of operations of the engine and to execute a model to derive an estimated catalyst emission based on the one or more engine signals and on an expected catalyst degradation. The controller is further configured to obtain one or more catalyst signals representative of catalyst performance, and to generate an adaptation signal configured to improve accuracy of the model based on the one or more catalyst signals. The controller is also configured to apply the adaptation signal and the estimated catalyst emission to generate an engine control signal.

A control system and method utilize an intake manifold absolute pressure (MAP) and an engine speed (RPM) sensor and a controller configured to obtain a model surface relating various measurements of the RPM sensor and valve overlap durations to modeled scavenging ratios of an engine, obtain a calibrated multiplier surface relating various measurements of the MAP and RPM sensors to measured scavenging ratios of the engine, determine a modeled scavenging ratio of the engine based on the measured engine speed and a known overlap duration using the model surface, determine a scavenging ratio multiplier based on the measured MAP and measured engine speed using the calibrated multiplier surface, determine the scavenging ratio of the engine by multiplying the modeled scavenging ratio by the scavenging ratio multiplier, and control the engine based on the scavenging ratio.

A system and method is provided for the use of the ion current signal characteristics for onboard cycle-by-cycle, cylinder-by-cylinder measurement. The system may also control the engine operating parameters based on a predicted NOx emission level, CO emission level, CO.sub.2 emission level, O.sub.2 emission level, unburned hydrocarbon (HC) emission level, cylinder pressure, or a cylinder temperature measurement according to characteristics of the ion current signal.

An internal combustion engine is described, and includes a method for operating that includes determining an observed carbon monoxide (CO) ratio in an exhaust gas feedstream, determining an observed in-cylinder scavenging based upon the observed CO ratio in the exhaust gas feedstream, and controlling, by a controller, control states for the variable cam phasing system to control opening times of engine intake valves in relation to closing times of engine exhaust valves based upon the observed in-cylinder scavenging.

Disclosed is a method for diagnosis of an oxygen probe for a combustion engine, with the steps: When an engine's fuel injection is inactive, measuring the output electric voltage from the oxygen probe; If the measured output electrical voltage of the oxygen probe is greater than a predetermined minimum voltage threshold, measuring a pressure prevailing in an intake distributor of the engine; If the measured pressure in the intake distributor is less than a predetermined minimum pressure threshold, increasing the pressure to a value greater than the predetermined minimum pressure threshold; Determining the time period between the time when the output electrical voltage of the probe falls below a second predetermined voltage threshold and the time when the output electrical voltage of the probe falls below a third predetermined voltage threshold; and diagnosing the oxygen probe depending on elapsed the time period.

An internal combustion engine-based system includes an internal combustion engine. The internal combustion engine-based system includes an engine interrupt connected to the engine. The engine interrupt is configured to selectively stop the operation of the engine. The internal combustion engine-based system includes a controller in communication with the engine interrupt. The internal combustion engine-based system includes a carbon monoxide detector in communication with the controller. The controller uses the engine interrupt to stop the operation of the engine when the carbon monoxide detector provides the controller with signals that are representative of a carbon monoxide level proximate the internal combustion engine that together form a trend of building carbon monoxide amounts over a set time interval.

A vehicle comprising a (diesel or gasoline) engine and aftertreatment system includes a powertrain control unit that identifies engine operating conditions expected to fulfill a demand for output from the engine. A first operating condition is expected to fulfill the demand with an exhaust stream having a first amount of NOx. A second operating condition is expected to fulfill the demand with an exhaust stream having a reduced amount of NOx as compared to the first amount of NOx. The powertrain control unit receives duty cycle information to control the engine to fulfill the demand per the second operating condition, yielding the reduced amount of NOx in the exhaust. Duty cycle information may include vehicle speed, location, a position sensor, a rotation sensor, ambient temperature, a characteristic feature of the duty cycle, dependency of load vs. time, information regarding an historical duty cycle, and temporal dependence of demand.

An air-fuel ratio control device switches a target air-fuel ratio from a lean set air-fuel ratio to a rich set air-fuel ratio after judging that an air-fuel ratio of an outflowing exhaust gas has become a stoichiometric air-fuel ratio and an oxygen storage amount of an exhaust purification catalyst has become a switching reference storage amount, and makes an average value of the target air-fuel ratio the stoichiometric air-fuel ratio to less than the lean set air-fuel ratio, from after the estimated value of the oxygen storage amount has become the switching reference storage amount or more until judging that the air-fuel ratio of the outflowing exhaust gas has become the stoichiometric air-fuel ratio if the estimated value of the oxygen storage amount becomes the switching reference storage amount or more before judging that the air-fuel ratio of the outflowing exhaust gas has become the stoichiometric air-fuel ratio.