A system includes a fuel control module and a valve control module. The fuel control module controls a fuel injector to stop fuel delivery to each cylinder of an engine in a vehicle when the vehicle is decelerating. The valve control module controls a valve actuator to actuate intake and exhaust valves of each cylinder of the engine between open and closed positions when fuel delivery to each cylinder of the engine is stopped. The valve control module controls the valve actuator to adjust an amount of airflow through each cylinder of the engine to a minimum amount when fuel delivery to each cylinder of the engine is initially stopped. The valve control module controls the valve actuator to adjust the amount of airflow through each cylinder of the engine to an amount greater than the minimum amount before fuel delivery to each cylinder of the engine is restarted.

A device and method for controlling an internal combustion engine having a catalytic converter. At least one actuating variable for the internal combustion engine is determined as a function of a system model of the catalytic converter and/or the internal combustion engine. The system model, a setpoint variable for the control and/or the actuating variable is adapted. Information about a modeled residual oxygen content in the exhaust gas downstream from the catalytic converter is determined using the system model. Information about an acquired residual oxygen content in the exhaust gas at the output of the catalytic converter is acquired. The information about the modeled residual oxygen content is compared with the information about the acquired residual oxygen content. A measure for an adaptation requirement is determined as a function of the result of the comparison.

A driving-side rotating body that rotates synchronously with a crankshaft of an internal combustion engine, a driven-side rotating body that is allowed to rotate relative to the driven-side rotating body and that rotates integrally with a camshaft that opens and closes an intake valve, and a phase adjustment mechanism for setting a relative rotation phase of the driving-side rotating body and the driven-side rotating body using a driving force of an electric motor are included. The phase adjustment mechanism is configured to be able to execute retarding control for setting the relative rotation phase to the retarding side until reaching a phase in which the internal combustion engine cannot be started and autonomous running is not possible even if fuel injection and ignition are performed in the internal combustion engine.

A state estimation apparatus includes: a rate calculating configured to calculate, based on both a flow rate and an air-fuel ratio of exhaust gas flowing into an oxygen storage catalyst, a rate of change in an oxygen storage amount in the oxygen storage catalyst; a limit calculating unit configured to calculate a limit rate which is a limit value for the rate of change; and a storage-amount updating unit configured to update, based on the rate of change and the limit rate, an estimated value of the oxygen storage amount. Moreover, the storage-amount updating unit is further configured to: update, when the rate of change does not exceed the limit rate, the estimated value based on the rate of change; and update, when the rate of change exceeds the limit rate, the estimated value based on the limit rate.

A method of controlling an air-fuel ratio in a pre-ignition (PI) situation, may include: monitoring, by a PI detector, whether PI occurs in a cylinder of a plurality of cylinders of an engine; and when the PI occurs in the cylinder of the plurality cylinders, controlling, by a controller, an air-fuel ratio of the cylinder in which the PI occurs to be smaller than a theoretical air-fuel ratio, and controlling an air-fuel ratio of a remaining cylinder of the plurality of cylinders in which PI does not occur to be larger than the theoretical air-fuel ratio.

A method of estimating the oxygen storage capacity of a catalyst includes providing an engine system having an internal combustion engine and an exhaust system having a catalyst and an oxygen sensor, providing a three-way catalyst observer model having a Kalman filter and a three-way catalyst kinetic model, estimating a three-way catalyst next time step state and a modeling error, linearizing the three-way catalyst observer model, filtering the estimated three-way catalyst next time step state, and calculating a covariance.

The abnormality diagnosis system 1 of a downstream side air-fuel ratio detection device 41, 42, comprises an air-fuel ratio control part 71 controlling an air-fuel ratio of an air-fuel mixture, an abnormality judgment part 72 judging abnormality of the downstream side air-fuel ratio detection device based on a characteristic of change of output of the downstream side air-fuel ratio detection device when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change, and an oxygen change calculation part 73 calculating an amount of change of an oxygen storage amount of the catalyst when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change. The abnormality judgment part does not judge abnormality of the downstream side air-fuel ratio detection device when the amount of change of the oxygen storage amount is less than a lower limit threshold value.

A control system for a fuel cutoff system of a motor vehicle includes a fuel cutoff module that generates a fuel cutoff signal for disabling a supply of fuel to an engine, in response to the fuel cutoff module detecting a deceleration fuel cutoff (DFCO) event. The control system further includes an oxygen storage module determining an amount of oxygen accumulated in a catalyst and comparing this amount to an oxygen storage capacity (OSC) of the catalyst, in response to the fuel cutoff module determining the DFCO event. The control system further includes an intake valve timing module generating a phasing signal to actuate a plurality of cam phasers to reduce a flow rate of oxygen to the catalyst, in response to the fuel cutoff module determining the DFCO event and the oxygen storage module determining that the amount of oxygen stored in the catalyst is less than the OSC.

A method for operating an internal combustion engine which has an exhaust-gas system in which a first exhaust-gas purification component and a second exhaust-gas purification component are arranged, and which has an opening-in point via which secondary air can be injected into the exhaust-gas system. The method is distinguished by the fact that an outlet concentration of the at least one exhaust-gas constituent prevailing at an outlet of the first exhaust-gas purification component is calculated by means of an outlet emissions model, and that an inlet concentration of the at least one exhaust-gas constituent prevailing at an inlet of the second exhaust-gas purification component is determined in a manner dependent on the calculated outlet concentration, and that the internal combustion engine is operated in a manner dependent on the thus determined inlet concentration of the at least one exhaust-gas constituent.

An engine system for a vehicle includes an internal combustion engine having an exhaust gas outlet, an exhaust system having a three-way catalyst and a switch-type post oxygen sensor, and an engine control module that controls the engine system. The engine control module includes a first control logic for estimating a three-way catalyst oxygen storage capacity based on a plurality of measured inputs, a second control logic for estimating aging effects of the switch-type post oxygen sensor, and a third control logic that calculates a filtered estimated three-way catalyst oxygen storage capacity for the three-way catalyst.