A control device for an engine is provided, which includes a combustion chamber formed by a cylinder and a piston, an intake air amount adjuster that adjusts an intake air amount supplied to the combustion chamber, a controller switchable of a combustion mode between a fuel-lean first combustion mode and a stoichiometric second combustion mode based on an engine operating state, and an intake air cooler that cools the intake air supplied to the combustion chamber. The controller controls the intake air cooler to start intake air cooling in response to a request for switching the combustion modes, and after the intake air cooling is started, controls the intake air amount adjuster to start the switching of the combustion modes, and then controls the intake air cooler and the intake air amount adjuster so that the switching of the combustion modes ends after the intake air cooling is finished.

Increasing engine idle speed, combined with modulating the timing of the exhaust valve during idling, increases heat transfer from the engine to aftertreatment systems to reduce the time required for the aftertreatment system to reach a minimum temperature for efficient operation. The resultant increases in heat transfer include an increase of at least 30% in the flow rate of exhaust gases and an increase of exhaust temperature by at least 25° C.

Systems and methods for unsticking intake and exhaust valves of an engine are described. In one example, valves that may be adjustably timed relative to an engine crankshaft position may be adjusted to unstick intake and/or exhaust valve that are stuck open or closed. In addition, fuel injection timing and spark timing may be adjusted in an effort to unstick intake and/or exhaust valves.

A control device includes an injection control unit, an ignition control unit, an idling stop control unit, and a boost control unit. The injection control unit executes a rich reduction control that makes an air-fuel ratio richer than a stoichiometric air-fuel ratio when the engine operation has been resumed by resuming supply of fuel to a combustion chamber. Further, the boost control unit is configured to execute a valve-closing keeping control that keeps a wastegate closed until a condition for cancelling the valve-closing keeping control has been satisfied by the engine operation that was performed after closing the wastegate during execution of a fuel cut-off control.

Based on an exhaust gas temperature on an upstream side acquired by an upstream temperature acquisition device, in performing control of supplying an unburned fuel to an oxidation catalyst device in a case where the exhaust gas temperature on the upstream side is lower than a low temperature, a control device performs control of adjusting at least one of an injection timing of a cylinder injection valve and opening-closing timing of an exhaust valve at least one of before and after the supplying control; raising a temperature of the exhaust gas that substantially free of unburned fuel discharged from the exhaust valve to be higher than the low temperature; and warming the oxidation catalyst device until a predetermined warming period has passed.

A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.

An engine control device is provided, which includes an engine body where a cylinder is formed, an exhaust passage through which exhaust gas discharged from the engine body circulates, a NO.sub.x sensor disposed in the exhaust passage and configured to detect a concentration of NO.sub.x in the exhaust gas, an injector configured to change an air-fuel ratio inside the cylinder, an in-cylinder temperature changer configured to change a temperature inside the cylinder, and a controller configured to control the injector and the exhaust shutter valve. The controller controls the injector based on a detection value of the NO.sub.x sensor to variably set the air-fuel ratio inside the cylinder, and when a particular condition that the air-fuel ratio inside the cylinder is leaner than a preset upper limit is satisfied, and causes the in-cylinder temperature changer to raise the temperature inside the cylinder.

A method for adaptation of a detected camshaft position of a camshaft in an internal combustion engine with: Detection of an ACTUAL gas signal in a gas space that is associated with the camshaft and is associated with a detected camshaft position; Processing of the gas signal to produce an ACTUAL gas criterion; Modeling of multiple simulated gas criteria, each of which is associated with a target camshaft position; Determination of a simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of an ACTUAL camshaft position that corresponds to the simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of a camshaft position correction value from the difference between the ACTUAL camshaft position determined and the detected camshaft position; Determination of corrected camshaft positions by correcting the detected camshaft positions with the camshaft position correction value.

An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves, an aftertreatment system to treat exhaust emission from the engine, and a controller coupled to at least one sensor and configured to control a variable valve actuation mechanism to provide variable engine braking for thermal management.

Methods and systems are provided for a dual function imaging device. In one example, a method may comprise imaging exhaust gas outside of a reverse engine condition via the imaging device. The imaging device may image a surrounding area during the reverse engine condition.