Methods and systems are provided for the estimation of an aircharge into a cylinder used to adjust an engine operating parameter, based on a manifold pressure signal stored in a buffer. In one example, a method may include sampling an intake manifold pressure sensor signal at even increments of time, stamping it with its corresponding crank angle and storing it in a buffer. The closest stored signal to the intake valve closing of a cylinder may be used to calculate its aircharge.

An engine control device includes processing circuitry configured to perform a base injection amount calculation process, a feedback process for correcting a base injection amount based on an output value of an integral element obtained using a difference of detection and target values of an air-fuel ratio as an input value, an injection valve operation process for operating a fuel injection valve based on the corrected base injection amount, a purge control process for operating an adjustment device to control a fluid flow rate from a canister to an intake passage, and a correction limiting process for limiting the output value of the integral element so that a decreasing correction rate of the base injection amount has a decreasing tendency when a charged air amount is decreased if the fluid flow rate is larger than zero.

A method for controlling operation of an internal combustion engine determines an estimated NOx value as a function of at least one engine operating parameter. The method also determines an actual NOx value using a NOx sensor positioned in an exhaust gas stream of the internal combustion engine. The method detects at least one condition indicative of whether or not the actual NOx value is accurate. The actual NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is accurate, while the estimated NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is inaccurate.

A method, an apparatus, a computer program, an engine intake system, and a vehicle are provided. The method is for controlling an air charge provided to a vehicular engine. The method comprises determining a target valve lift of an inlet valve in a continuously variable valve lift system based, at least in part, on: a required air charge for a given torque request; and an estimate of a variable pressure of an engine intake manifold for a time when the inlet valve is to be actuated in accordance with the target valve lift. The method also comprises controlling actuation of the inlet valve in the continuously variable valve lift system in accordance with the determined target valve lift.

Methods and systems are provided for providing passive boost pressure monitoring for slow response with higher confidence. A response time of a boost pressure feedback control loop following a boost pressure deviation that is triggered by either system disturbances or operator torque demand is monitored. Slow boost behavior is correlated with boost control degradation affecting drivability and emissions.

A control device for an internal-combustion engine includes circuitry. The circuitry is configured to calculate, in accordance with an operating state of the internal-combustion engine, a basic supercharging pressure of intake gas generated by a supercharger provided in the internal-combustion engine. The circuitry is configured to acquire a flow rate change state parameter that correlates with a change state of the flow rate of the intake gas controlled by a flow rate control mechanism provided in the internal-combustion engine. The circuitry is configured to calculate a correction value in accordance with the flow rate change state parameter. The circuitry is configured to calculate an estimated supercharging pressure of the intake gas by correcting the basic supercharging pressure with the correction value. The circuitry is configured to control operation of the internal-combustion engine using the estimated supercharging pressure.

A controller for an internal combustion engine includes a processing circuit configured to execute a calculating process that calculates a returned air amount and an operating process that operates a fuel injection valve so that an air-fuel ratio of a mixture that is burned in a combustion chamber is controlled to a target value. The operating process includes under a condition in which the returned air amount is increased, having the fuel injection valve inject fuel increased in amount from a constant fuel amount, which is an amount of fuel injected when the returned air amount is unchanged, and under a condition in which the returned air amount is decreased, having the fuel injection valve inject fuel decreased in amount from the constant fuel amount.

An apparatus for controlling fuel injection according to an exemplary embodiment of the present disclosure may include a driving information detector for detecting driving information including a fresh air amount flowing into an intake manifold through a throttle valve, a recirculation gas amount supplied to the intake manifold through an exhaust gas recirculation apparatus, a fuel vapor amount supplied to the intake manifold through a canister purge system, a gas amount supplied to a cylinder from the intake manifold, an internal pressure of the intake manifold, an internal temperature of the intake manifold, a pressure of a recirculation gas and a temperature of the recirculation gas; an injector for injecting fuel into the cylinder; and a controller for calculating gas amount supplied to the cylinder at a next intake stroke from the driving information and controlling fuel amount injected by the injector at the next intake stroke to be a target air-fuel ratio.

Systems and methods are provided for increasing the accuracy of air charge estimation for a cylinder that is selectively deactivatable. A controller may deactivate the cylinder in accordance with a firing pattern selected based on torque demand. An air charge estimate of the firing cylinder is then adjusted based on whether the cylinder was fired or skipped on a previous engine cycle when operating according to the selected firing pattern.

An EGR apparatus includes an EGR passage to allow part of exhaust gas discharged from an engine to an exhaust passage to flow as EGR gas into an intake passage; an EGR valve to regulate an EGR flow rate in the EGR passage; various sensors for detecting an engine running state; and an ECU to control the EGR valve based on the detected running state to diagnose abnormality in the EGR valve. The ECU calculates a reference intake pressure according the detected engine rotation speed and load by reference to a reference intake pressure map showing a relationship of the reference intake pressure to engine rotation speed, and engine load, and determine whether or not the EGR valve has abnormality in opening/closing by comparing the reference intake pressure with the detected intake pressure.