A cylinder-inflow EGR gas amount is estimated, a misfire limit EGR gas amount is calculated on the basis of an engine operation state, and the misfire limit EGR gas amount is compared with the cylinder-inflow EGR gas amount to predict whether a misfire occurs. When the misfire is predicted, a misfire avoidance control is executed. Further, an actual misfire countermeasure effect amount in a case of the execution of the misfire avoidance control is calculated, and the actual misfire countermeasure effect amount is compared with a required misfire countermeasure effect amount to determine whether the misfire is avoidable when the misfire avoidance control is executed. If the misfire is unavoidable even if the misfire avoidance control is executed, a delay restriction value of an ignition timing to avoid the misfire is calculated, and the amount of a delay in the ignition timing is restricted using the delay restriction value.

The invention relates to a method for modeling a compressor intake temperature and/or a compressor discharge temperature of a compressor taking into account a compressor surge, wherein the method comprises: Identifying a pressure gradient across the compressor Identifying a mass flow gradient across the compressor Establishing that the compressor surge is present when the pressure gradient exceeds an upper pressure gradient limit and the mass flow gradient falls below a lower mass flow gradient limit; and Identifying the compressor intake temperature with a temperature correction factor that is dependent on the compressor surge and/or identifying the compressor discharge temperature on the basis of a corrected compressor discharge pressure that is dependent on the compressor surge.

A method of predicting manifold air pressure in an internal combustion engine during idle comprising the steps of receiving an idle air control (IAC) duty cycle value from an idle air controller, receiving an atmospheric pressure, and predicting a manifold pressure in an engine control unit based on the IAC duty cycle value and the atmospheric pressure.

A process for monitoring turbocharger operation in a machine is disclosed. The machine includes a power source having an intake manifold for supplying the power source with air and a plurality of turbochargers. Each turbocharger includes an air inlet passageway to receive air, a plurality of pressure sensors arranged within the inlet passageway, a compressor configured to pressurize air, an air outlet passageway to direct pressurized air from the compressor to the intake manifold, and an exhaust turbine operably driven by exhaust gas from the power source and coupled to the compressor by a turbine shaft. The process includes monitoring the differential pressure across the air inlet passageway for each turbocharger, comparing the differential pressures for each turbocharger and indicating an anomaly in turbocharger speed when the differential pressure for one turbocharger exceeds the differential pressure for another turbocharger by a threshold amount.

A device for computing correction for control parameter in a manufacturing process executed on a manufacturing apparatus includes circuitry which acquires an index representing fluctuation in a manufacturing apparatus, acquires an apparatus model and a process model, acquires an output from a sensor in the manufacturing apparatus, transforms the output into first fluctuation for a process element, transforms the index into second fluctuation for the process element based on the apparatus model, computes fluctuation for performance indicator from the first and second fluctuation based on the process model, computes correction for the performance indicator from control range for the performance indicator and the fluctuation for the performance indicator, and converts the correction for the performance indicator into correction for each process element based on the process model such that correction for control parameter in process executed on the manufacturing apparatus is computed from the correction converted for each process element.

The present disclosure relates to internal combustion engines. The teachings thereof may be embodied in methods and devices for controlling the combustion processes taking place in the cylinders of an internal combustion engine. A method for controlling a combustion process in an internal combustion engine may include: measuring an actual camshaft position; measuring the actual rail pressure; calculating a phase correction value based on the measured actual rail pressure and a mass of fuel to be injected; calculating corrected actual camshaft positions based on the measured actual camshaft position and the respective phase correction value; calculating a mass of air depending on the determined corrected actual camshaft position; and calculating a fuel injection mass based on the mass of air determined for each cylinder.

A target compression ratio ε(t+Tact) after a prescribed time Tact has expired from a current point of time is calculated from an intake air volume drawn into a cylinder after expiration of the prescribed time Tact from the current point of time. A control command to an electric motor that drives a variable compression ratio mechanism is calculated so as to bring an actual compression ratio εr(t+Tact) after the prescribed time Tact into accordance with the target compression ratio ε(t+Tact) after the prescribed time Tact. This enables the actual compression ratio to follow the target compression ratio accurately.

A method for controlling a forced induction engine includes: determining a first air pressure upstream of an air compressor, the air compressor supplying compressed air to the engine; determining a second air pressure downstream of the air compressor; determining a limit air flow rate to the engine corresponding to the surge limit of the air compressor based at least in part on the first and second air pressures; and controlling a throttle valve actuator to position the throttle valve at a position providing an air flow rate that is greater than or equal to the limit air flow rate. A vehicle power pack having a control unit implementing the method and a vehicle having the vehicle power pack are also disclosed.

Computational models and calculations relating to trapped and scavenged air per cylinder (APC) improve scavenging and non-scavenging operational modes of internal combustion engines as well as the transition there-between. Data from sensors which include engine speed, manifold air pressure, barometric pressure, crankshaft position, and valve state are provided to a pair of artificial neural networks. A first neural network utilizes this data to calculate the nominal volume of gas, i.e., air trapped in the cylinder. A second neural network utilizes this data to calculate the trapping ratio. The output of the first network is utilized with the ideal gas law to calculate the actual mass of trapped APC. The actual mass of trapped APC is also divided by the trapping ratio calculated by the second network to determine the total APC and is further utilized to calculate the scavenged APC by subtracting the trapped APC from the total APC.

The invention relates to a method for determining the pressure P.sub.avcm upstream of a mechanical compressor (3) equipped with a double supercharging circuit of a combustion engine. The pressure P.sub.avcm is determined by a dynamic model based on a law of conservation of flow rate in the volume upstream of the mechanical compressor. The model links the pressure P.sub.avcm upstream of the mechanical compressor (3) to a temperature T.sub.avcm upstream of the mechanical compressor (3), to a boost pressure P.sub.sural and boost temperature T.sub.sural on the intake side of the engine, and to an openness Bypass of the bypass valve (4).