A canister purge control method for a vehicle can reduce the number of components of an active purge system provided in the vehicle. An active purge operation is performed using a pressure value measured by an intake pressure sensor, instead of a pressure value measured by a rear-end pressure sensor, after a purge control solenoid valve is fully opened.

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.

Methods and systems are provided for converting an asymmetric sensor response of an exhaust gas sensor to a symmetric response. In one example, a method includes adjusting fuel injection responsive to a modified exhaust oxygen feedback signal from an exhaust gas sensor, where the modified exhaust oxygen feedback signal is modified by transforming an asymmetric response of the exhaust gas sensor to a symmetric response. Further, the method may include adapting parameters of an anticipatory controller of the exhaust gas sensor based on the modified symmetric response.

A method and apparatus for operating an internal combustion engine is disclosed. A signal generated by the oxygen concentration sensor is converted into a first signal indicative of an air/fuel ratio in the engine cylinder. A second signal indicative of an expected air/fuel ratio in the engine cylinder due to a fuel injection is generated and filtered to obtain a filtered signal and used to operate the engine. The filtered signal is obtained by sampling values of the first and second signals. A time constant is calculated based on the sampled values of the first and second signals and a value of the first signal sampled during a preceding control cycle. A value of the filtered signal is calculated based on the calculated time constant, the sampled value of the second signal and a value of the filtered signal calculated during the preceding control cycle.

A controller for an internal combustion engine includes processing circuitry. The processing circuitry performs a dither control process and a multi-injection process. Multiple injections in the multi-injection process includes a first injection and a second injection performed at a timing retarded from the first injection. The dither control process includes at least one of a process performed on a cylinder changed to a lean combustion cylinder so that a reduction amount of fuel injected through the first injection is greater than a reduction amount of fuel injected through the second injection and a process performed on a cylinder changed to a rich combustion cylinder so that an increase amount of fuel injected through the first injection is greater than an increase amount of fuel injected through the second injection.

Methods and systems are provided for an oxygen sensor heater. In one example, a method may include applying a less than maximum duty cycle of voltage to the oxygen sensor heater during an engine cold start (e.g., when a temperature of the oxygen sensor is less than its light-off temperature) and adjusting the applied duty cycle of voltage to maintain a constant amount of power. In this way, the oxygen sensor may be heated at a constant rate even as a resistance of the oxygen sensor heater increases, decreasing an amount of time before the oxygen sensor reaches its light-off temperature.

Methods and systems are provided for converting an asymmetric sensor response of an exhaust gas sensor to a symmetric response. In one example, a method includes adjusting fuel injection responsive to a modified exhaust oxygen feedback signal from an exhaust gas sensor, where the modified exhaust oxygen feedback signal is modified by transforming an asymmetric response of the exhaust gas sensor to a symmetric response. Further, the method may include adapting parameters of an anticipatory controller of the exhaust gas sensor based on the modified symmetric response.

In the disclosure, an F/B correction coefficient correcting a fuel injection amount so that a detected equivalence ratio detected by an LAF sensor becomes a target equivalence ratio is calculated by using a feedback control containing a predetermined gain, and a reference F/B correction coefficient is further set. By changing a valve overlap characteristic between an intake valve and an exhaust valve in a supercharging state, a scavenging control that scavenges a combustion chamber by blow-by of intake air is executed. During the scavenging control, when the F/B correction coefficient is changing relative to the reference F/B correction coefficient in a direction of further correcting the fuel injection amount to a rich side, the gain of the feedback control is reduced.

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.

An air-fuel ratio controller of an internal combustion engine includes an open-loop processor setting a base injection amount, a feedback processor calculating a feedback operation amount, an increase processor performing an increase correction on the base injection amount when a temperature of the internal combustion engine is a specified temperature or lower, an operation processor operating a fuel injection valve based on the corrected base injection amount and that is corrected using the feedback operation amount and a learning value, and an update processor updating the learning value. If the increase processor performs the increase correction, the update processor updates the learning value to increase an increase correction rate of the base injection amount when a temperature of the cylinder wall surface is high.