A method for predictive open-loop and/or closed-loop control of an internal combustion engine with control variables pursuant to a model of the engine with characterizing variables and a control circuit for the control variables. The control variables are adjusted in an open-loop or closed-loop manner by measuring actual values and specifying target values of the characterizing variables and, optionally, depending on the boundary and/or environmental and/or ageing conditions. The characterizing variables are controlled pursuant to a model of the engine with the characterizing variables and a control circuit with the control variables. The controlling is part of a model-based predictive control, wherein the characterizing variables of the engine model are calculated and the control variables of the engine are adjusted in a predictively controlled manner. A model-based predictive non-linear controller is used for the controlling, which is constructed in a modular manner with a number of model-based predictive control modules.

An engine control apparatus controls an engine, by generating first and second instruction values to adjust an MAF of fresh air supplied to the engine and an MAP indicating a pressure of air supplied to the engine to respective target values, based on measured values of a first sensor which detects the MAF and a second sensor which detects the MAP, regardless of limiting conditions related to a totally closed or fully open state of an EGR and an VNT, switching a supplying destination of the measured values of the first and second sensors for a certain time after the generated first or second instruction value saturates, and generating the first and second instruction values to adjust the MAF and the MAP to the respective target values, based on the measured values of the first and second sensors, under the limiting conditions, when the switching occurs.

Downstream side air-fuel ratio sensor signal based adaptive air-fuel ratio control. When the air-fuel ratio detected by the downstream side air-fuel ratio sensor is maintained lean unduly, a stuck learning control is performed to decrease a learning value to lower the air-fuel ratio. Adaptive learning value update control is performed based on the downstream side air-fuel ratio sensor signal to increase the learning value when an upstream air-fuel ratio deviates to the rich side and to decrease the learning value when the upstream air-fuel ratio deviates to the lean side. It is judged that the downstream side air-fuel ratio sensor is abnormal when a certain value or more of decrease of the learning value and a certain value or more of increase of the learning value are repeated.

A control device for an internal combustion engine comprises an air-fuel ratio control part configured to control the air-fuel ratio of the exhaust gas and a heating control part configured to control the heating of the air-fuel ratio sensors. The heating control part controls the sensor heaters so that the temperature of the upstream air-fuel ratio sensor becomes less than the activation temperature and so that the temperature of the downstream air-fuel ratio sensor becomes the activation temperature or more while the internal combustion engine is stopped by the automatic stop function. The air-fuel ratio control part controls the exhaust air-fuel ratio based on the outputs of the two air-fuel ratio sensors during engine operation and control the air-fuel ratio temporarily based on only the output of the downstream air-fuel ratio sensor after the internal combustion engine has been restarted after automatic stop.

An electronic control unit of the present invention includes: a demand generation level that generates and outputs a demand value concerning various kinds of functions; a physical quantity mediation level that aggregates and mediates the demand value for each predetermined physical quantity; and a controlled variable setting level that sets a controlled variable of the actuator based on the mediated demand value and transmits a signal in a single direction from a higher level to a lower level. A controlled variable mediation level that aggregates and mediates demand values expressed with controlled variables of the actuators set on the controlled variable setting level and a demand value transmitted from the demand generation level not through the physical quantity mediation level, together with demand values mediated by the physical quantity mediation level is provided below the controlled variable setting level.

A method for operating an internal combustion engine in an idle mode, in which an ignition angle and/or an air quantity of the internal combustion engine is influenced and/or is modified as a function of an idle rotation speed of the internal combustion engine. The ignition angle and/or the air quantity and/or a fuel quantity for at least one combustion chamber of the internal combustion engine is modified as a function of at least one variable characterizing a combustion event in the combustion chamber.

Feedback control is executed based on a measured CA10 and a measured CA50 that are calculated based on measured data for MFB. During steady operation a correlation index value I.sub.RA that shows a degree of correlation between the measured data and reference data corresponding thereto is calculated. During transient operation, a correlation index value I.sub.AA that shows a degree of correlation between the measured data and measured data that is measured immediately prior to the measured data is calculated. If the correlation index value I.sub.RA or the correlation index value I.sub.AA is less than a determination value I.sub.th, control is performed to prohibit reflection in the aforementioned feedback control of each of the measured CA10 and the measured CA50 which are measured in the combustion cycle in which the relevant correlation index value is calculated.

Method for adjusting the air-fuel ratio in the exhaust gas of a direct injection internal combustion engine, wherein the combusting fuel injection is divided into a plurality of individual injections, and wherein the air-fuel ratio in the exhaust gas of the internal combustion engine for a given load (PMI) is predictively adjusted by at least one model, by adjusting the position of the centroid of heat release conversion rates and the injection amount of the total combusting fuel injection, to a value that is necessary for the regeneration of an NOx storage catalytic converter in the exhaust system of the internal combustion engine.

A control apparatus for an internal combustion engine is configured to: calculate measured data of MFB based on in-cylinder pressure detected by an in-cylinder pressure sensor; execute engine control based on a measured value of a specified fraction combustion point that is calculated based on the measured data of MFB; and calculate a first correlation index value for the measured data (current data) and the reference data of MFB and a second correlation index value for the current data and the immediately preceding past data. The engine control is suspended that uses the measured data of the specified fraction combustion point based on the current data when both of the first correlation index value and the second correlation index value are less than a determination value.

Downstream side air-fuel ratio sensor signal based adaptive air-fuel ratio control. When the air-fuel ratio detected by the downstream side air-fuel ratio sensor is maintained lean unduly, a stuck learning control is performed to decrease a learning value to lower the air-fuel ratio. Adaptive learning value update control is performed based on the downstream side air-fuel ratio sensor signal to increase the learning value when an upstream air-fuel ratio deviates to the rich side and to decrease the learning value when the upstream air-fuel ratio deviates to the lean side. It is judged that the downstream side air-fuel ratio sensor is abnormal when a certain value or more of decrease of the learning value and a certain value or more of increase of the learning value are repeated.