A control device of an internal combustion engine calculates on the basis of the air-fuel ratio difference a correction for the estimated fuel supply amount correction for correcting the estimated fuel supply amount to make the estimated and detected air-fuel ratios correspond to each other and calculates correction values for the fuel supply difference compensation and the air amount detection difference compensation by dividing the correction value for the estimated fuel supply amount correction, using the fuel supply and air amount detection difference proportions, and performing the air-fuel ratio control, using the corrected estimated fuel supply and detected air amounts. The correction value for the estimated fuel supply amount correction is divided to the correction values for the fuel supply difference compensation and the air amount detection difference compensation such that a value equivalent to the air-fuel ratio difference becomes equal to the air-fuel ratio difference, using these correction values.

An engine system incorporating an engine, one or more sensors, and a controller. The controller may be connected to the one or more sensors and the engine. The one or more sensors may be configured to sense one or more parameters related to operation of the engine. The controller may incorporate an air-path state estimator configured to estimate one or more air-path state parameters in the engine based on values of one or more parameters sensed by the sensors. The controller may have an on-line and an off-line portion, where the on-line portion may incorporate the air-path state estimator and the off-line portion may configure and/or calibrate a model for the air-path state estimator.

A method for operating a compression ignition engine includes forming a combustible mixture by mixing generally homogeneously a first fuel and air and introducing this mixture into the at least one cylinder, compressing the combustible mixture with the piston in a compression stroke, injecting a second fuel to the combustible mixture at an injection-time of the second fuel during the compression stroke but before start of combustion, and continuing the compression stroke until combustion starts at those locations in the at least one cylinder where concentration of the second fuel is highest and/or the temperature of the mixture is the highest. Emission of the cylinder and/or mechanical stress of the cylinder caused by the combustion are monitored, and if emissions and/or mechanical stress are above respective predetermined thresholds, individually for the cylinder, the amount and/or the timing of the second fuel injected, and/or temperature of the cylinder charge is changed.

Approaches for predicting parameters contributing to engine emissions are described. In an example, the values of control parameters may be obtained from the vehicle sensors. Based on the obtained values of the control parameters, estimated emission value may be determined pertaining to a correlation criterion reflecting a predetermined relationship between the obtained control parameter and engine emission. Further, the contribution index of each of the individual control parameters may be identified. Further, based on the estimated emission value and the contribution index, aggregated emission value corresponding to the exhausted emission from the engine for particular trip may be calculated.

A method for creating an emissions model of an internal combustion engine. The method begins with a provision of a plurality of measurement series at an internal combustion engine. There then follows a filtering of the measurement series using various low-pass filters, and ascertaining, from the filtered measurement series, those measurement series, when provided as an input variable for the emissions model during optimization of the emissions model, the smallest deviation from predicted emissions of the emissions model for measured emissions is achieved.

A method for analyzing an amount of substance emitted as a result of the operation of a functional unit of a utility vehicle includes generating signals from a signal source independently of the amount of substance, transmitting the signals to a data processing apparatus as input data for determining the emitted amount of substance, processing the input data in the data processing apparatus to form output data which represent the emitted amount of substance, and transferring the output data as transfer data to a storage unit of a digital distributed ledger.

An engine system includes an engine with an intake manifold and an exhaust manifold, a turbocharger including a turbine in communication with the exhaust manifold and a compressor in communication with the intake manifold, and a regulator configured to control a flow of exhaust gas through the turbine. A controller of the engine system is operably connected with the regulator and is configured to monitor an engine load and an exhaust gas temperature during operation of the engine, identify a proscribed engine NOx emissions level based on the engine load and the exhaust gas temperature and, when the proscribed engine NOx emissions level is identified, modify the flow of exhaust gas through the turbine to reduce the energy extracted from the exhaust gas by the turbine and reduce a drive power provided to the compressor, thereby reducing a flow of intake air provided to the intake manifold by the compressor.

Methods and systems for monitoring a NOx sensor for a NOx offset value are described. In one example, the NOx offset value may be based on a minimum NOx concentration observed over an entire drive of a vehicle. The NOx offset monitor may be inhibited in response to inferring or detecting a presence of NH.sub.3 in an exhaust system.

According to the invention, a method for air path control of a combustion engine is provided, comprising an EGR valve and a VGT turbine. The method comprises providing a cost function of a measured delta pressure between engine intake and exhaust manifold; determining a gradient of the cost function as a function of a delta pressure set point, determining a gradient of a constraint function for estimated NOx emission level, turbine rate; and oxygen level as a function of delta pressure; real time controlling the NOx emission level and delta pressure to respective desired NOx and delta pressure set points by adjusting the EGR valve and/or the VGT turbine, wherein the delta pressure set point is adjusted according to an integration of a selected gradient direction of the cost function selected from the determined one or more of the gradients, wherein the determined gradients are prioritized in the order of turbine rate, oxygen level and NOx emission level; and wherein NOx emission level and or a turbine rate and or oxygen levels are constrained; and wherein the adjusted delta pressure set point is perturbed in an extremum seeking operation on the cost function.

Control of a spark ignited internal combustion in response to an exhaust manifold pressure measurement of an engine is disclosed. An engine out NOx amount for at least one cylinder is determined at least in part in response to the exhaust manifold pressure measurement and a brake mean effective pressure of the at least one cylinder. An operating condition of the engine is adjusted in response to the engine out NOx amount.