Provided is an engine control device for correcting output characteristics of an oxygen sensor and performing air-fuel ratio feedback control. The engine control device includes various sensors for detecting operating state information of an engine, an oxygen sensor, and air-fuel ratio feedback controller to adjust an amount of fuel injected into the engine, on the basis of the operating state information and an output voltage value of the oxygen sensor, wherein the air-fuel ratio feedback controller calculates, in accordance with the operating state information based on detection results from the various sensors, a coefficient for correcting the output voltage value, implements air-fuel ratio feedback control on the basis of an air-fuel ratio feedback control correction amount calculated using a corrected oxygen sensor output voltage value calculated on the basis of the coefficient, and adjusts the amount of fuel injected into the engine.

A plant control system comprises a target value calculating part calculating a target value r of a control output x of a plant, a target value correcting part correcting the target value so as to calculate a corrected target value w, and a feedback controller determining a control input. The target value correcting part, if making the control output change to the target value, sets the corrected target value so that an amount of correction of the target value becomes equal to or less than a predetermined value, then changes the corrected target value so that the amount of correction of the target value becomes larger than the predetermined value, then changes the corrected target value so that the amount of correction of the target value becomes equal to or less than the predetermined value before the control output reaches the target value.

A basic opening (A0) of an EGR control valve (22) is set, based on a current engine operation state. A differential pressure (P1) across the EGR control valve (22) is calculated, based on an actual exhaust system temperature (T1) sensed by an exhaust temperature sensor (33). A reference differential pressure (P0) is calculated, which is a differential pressure across the EGR control valve (22) in a steady state corresponding to the current engine operation state. A reference pulsation amplitude (D) is calculated, which is an amplitude of pulsation of the reference differential pressure (P0). The basic opening (A0) is corrected, based on the differential pressure (P1), the reference differential pressure (P0), and the reference pulsation amplitude (D).

A control apparatus for an internal combustion engine having an exhaust gas purification device which is arranged in an exhaust passage and includes a NOx storage reduction (NSR) catalyst. The control apparatus, when the air fuel ratio of the air-fuel mixture is shifted from a lean air fuel ratio to the stoichiometric air fuel ratio, determines a predetermined NO.sub.x amount so as to be larger when the temperature detected by the first detection unit is high in comparison with when the detected temperature is low, and when the storage amount of NO.sub.x in the NSR catalyst is larger than the predetermined NO.sub.x amount, performs the rich spike processing and then controls the air fuel ratio to the stoichiometric air fuel ratio, whereas when otherwise, controls the air fuel ratio to the stoichiometric air fuel ratio without performing the rich spike processing.

A control system and method utilize an exhaust oxygen (O2) sensor and a controller configured to operate a turbocharged engine in a scavenging mode, and while the operating the engine in the scavenging mode: command a target in-cylinder air/fuel ratio (FA) for achieving a target exhaust gas FA, adjust the measurement of the exhaust O2 sensor based on a scavenging ratio and the target in-cylinder FA to obtain a modified O2 concentration, adjust an exhaust system temperature modeled by a thermal model to obtain a modified exhaust system temperature, and adjust the target in-cylinder FA based on the modified O2 concentration and the modified exhaust system temperature.

A process and a system for preventing pre-ignition in an internal combustion engine (ICE) includes detecting an ionization level of a combusted gas from a cylinder of the ICE during gas exchange and for a given combustion cycle i. When the ionization level is greater than a reference ionization level a pre-ignition countermeasure prior to and/or during an immediate subsequent combustion cycle i+1 is executed. The ionization sensor may be part of a spark initiating device of the ICE or be a separate ionization sensor.

Provided is an engine control device for correcting output characteristics of an oxygen sensor and performing air-fuel ratio feedback control. The engine control device includes various sensors for detecting operating state information of an engine, an oxygen sensor, and air-fuel ratio feedback controller to adjust an amount of fuel injected into the engine, on the basis of the operating state information and an output voltage value of the oxygen sensor, wherein the air-fuel ratio feedback controller calculates, in accordance with the operating state information based on detection results from the various sensors, a coefficient for correcting the output voltage value, implements air-fuel ratio feedback control on the basis of an air-fuel ratio feedback control correction amount calculated using a corrected oxygen sensor output voltage value calculated on the basis of the coefficient, and adjusts the amount of fuel injected into the engine.

A process and a system for preventing pre-ignition in an internal combustion engine (ICE) includes detecting an ionization level of a combusted gas from a cylinder of the ICE during gas exchange and for a given combustion cycle i. When the ionization level is greater than a reference ionization level a pre-ignition countermeasure prior to and/or during an immediate subsequent combustion cycle i+1 is executed. The ionization sensor may be part of a spark initiating device of the ICE or be a separate ionization sensor.

A fuel control system for an engine includes a closing module and a purge control module. The closing module commands closing of a purge valve in response an engine speed transitioning from greater than a predetermined speed to less than the predetermined speed while the purge valve is in an open state. The predetermined speed is less than a predetermined target speed of the engine and is greater than zero. The purge control module transitions the purge valve from the open state to a closed state in response to the command.

The invention relates to a method and to a regulating device for regulating an air-fuel ratio of an internal combustion engine (10), wherein an exhaust-gas composition of an exhaust gas of the internal combustion engine (10) is determined by virtue of an actual probe signal, which is dependent on the exhaust-gas composition, being detected by means of an exhaust-gas probe (22) and the exhaust-gas composition being determined as a function of the actual probe signal by means of a characteristic curve or a calculation rule, and wherein the determined exhaust-gas composition is compared with a setpoint value or a threshold value, the attainment or exceedance of which triggers a manipulation of the air-fuel ratio supplied to the internal combustion engine (10), wherein, in order to take into consideration at least one disturbance variable which affects the actual probe signal, a safety margin (S) is defined which is applied to the characteristic curve or calculation rule, to the actual probe signal or to the setpoint value or threshold value. It is provided that an evaluation of a present accuracy of the at least one disturbance variable and/or of a present influence of the at least one disturbance variable on the probe signal is performed, and the safety margin (S) owing to the at least one disturbance variable is defined as a function of the evaluation.