A controller for an internal combustion engine is configured, when the speed of combustion of a fuel in a cylinder changes as the property of the fuel injected from a fuel injection valve changes, to change a combustion limit excess air ratio that is a target value of a fuel injection amount feedforward control according to a first relationship that the combustion limit excess air ratio increases as the speed of combustion of the fuel in the cylinder increases. The controller is also configured, when the speed of combustion of the fuel in the cylinder changes as the property of the fuel injected from the fuel injection valve changes, to change the value of a combustion limit combustion speed parameter that is the target value of a fuel injection amount feedback control according to a second relationship that the speed of combustion of the fuel in the cylinder corresponding to a combustion limit increases as the speed of combustion of the fuel in the cylinder increases.

This disclosure provides a system and method for controlling internal combustion engine system to reduce operation variations among plural engines. The system and method utilizes single-input-single-output (SISO) control in which a single operating parameter lever is selected from among exhaust gas recirculation (EGR) fraction and charge air mass flow (MCF), and a stored reference value associated with the selected lever is adjusted for an operating point in accordance with a difference between a measured emissions characteristic and a pre-calibrated reference value of the emissions characteristic for that operating point. Adjusting the selected operating parameter lever towards the theoretical pre-calibrated reference value of the operating parameter lever for each of plural operating points can reduce engine-to-engine variations in engine out emissions.

In exemplary embodiments, methods, and systems for multivariable torque control of a vehicle are provided. The method includes configuring a processor disposed of in a multivariable controller to determine a set of references associated with Exhaust Gas Recirculation (EGR) by implementing an algorithm based on engine temperature and at least one reference associated with the EGR to generate commands for the control of a set of actuators; Optimizing at least one cam phase position by the control based on a generated command to apply an appropriate level of engine torque for vehicle propulsion; Restricting an allowable range of cam phases associated with operations of an EGR valve for a set of cams based on amounts of humidity and EGR introduced by the EGR valve during an internal combustion phase of vehicle operation; and providing an amount of propulsion torque by an engine in accordance with instructions provided by the processor.

A system and method of integrating an engine having dynamic skip fire control with an exhaust gas recirculation system in a turbocharged internal combustion engine is described. An engine control system determines an appropriate firing pattern based at least in part on a desired exhaust gas recirculation flow rate. Signals from sensors in the intake manifold and exhaust system may also be used as part of a feedback loop to determine a desired exhaust gas recirculation flow rate.

Methods and systems are provided for coordinating operation of a high pressure EGR control loop with a boost pressure control loop. In one example, following a tip-in, turbine vane position may be adjusted as a function of a maximum permissible exhaust pressure upstream of a turbocharger turbine. The maximum permissible exhaust pressure may be determined as a function of a HP EGR valve position at the time of the tip-in.

A method and system for controlling an EGR valve for a vehicle may include an adjusting step of reducing the amount of air flowing into an engine at operation points of the engine lower than a predetermined value at each of the operation points by a controller; a learning step of maintaining, as a reduction-learning amount, a reduction amount of the amount of air from the predetermined value before a malfunction occurs, by the controller, when a malfunction occurs in the engine due to the reduction in the amount of air; a compensating step of determining a compensating air amount at each of the operation points by applying the reduction amount to the predetermined value by the controller; and an EGR controlling step of controlling an EGR-opening amount to satisfy the compensating air amount for a current operation time after the compensating step.

The present invention suppresses the worsening of stability due to a variation in EGR amounts between cylinders in a spark ignition engine. An engine control device for controlling a spark ignition engine equipped with an EGR means for recirculating exhaust gas in a combustion chamber and an air-fuel-ratio detection means for detecting the air-fuel ratio in each cylinder, the engine control device being characterized by being equipped with a means for changing the parameters for ignition control of a rich cylinder, when the air-fuel ratio of cylinders varies and there are richer cylinders and leaner cylinders relative to a prescribed air-fuel ratio during the execution of exhaust gas recirculation by the EGR means.

Systems are provided for detecting a change in performance of an engine component. In one example, a system includes a first pressure sensor of a first exhaust manifold coupled to a first subset of cylinders of an engine, a second pressure sensor of a second exhaust manifold coupled to a second subset of cylinders of the engine, a passage coupling the first exhaust manifold to an intake manifold, and a controller configured to detect a change in performance of any cylinder of the engine based on frequency content from the first pressure sensor and from the second pressure sensor during both a first mode where no exhaust gas from the first exhaust manifold is provided to the intake manifold, and during a second mode where all exhaust gas from the first exhaust manifold is provided to the intake manifold, and adjust an operating parameter responsive to the change in performance.

An apparatus for controlling an EGR valve, includes: a measurement unit to measure at least one operation condition of an engine system; a fresh air amount setting unit to set a target amount of fresh air based on the operation condition; a fresh air amount sensor to measure a current amount of fresh air introduced through an intake line; a control calculation unit to set a signal for controlling an opening degree of the EGR valve so that the current amount of fresh air follows the target amount of fresh air; and an identifier to simulate an input and an output of the engine system, and output engine system input-output sensitivity which is a ratio of a change rate of the current amount of fresh air to a change rate of the opening degree of the EGR valve.

A method of controlling exhaust gas recirculation (EGR) for controlling recirculation of exhaust gas discharged from a combustion chamber of an engine includes: a data obtaining operation of obtaining data about an engine state and a gas supply state; a current EGR rate calculating operation of calculating a current EGR rate of supply gas based on the data; a demand EGR rate setting operation of setting a demand EGR rate matched with the data in a pre-made target EGR rate map; an error calculating operation of calculating a difference between the demand EGR rate and the current EGR rate; and a control operation of making the current EGR rate follow the demand EGR rate by changing a recirculation rate of the exhaust gas by adjusting an inhalation side pressure of the supply gas according to the difference.