Methods and systems are provided for boosted engines. In one example, a method for a boosted engine method may include storing compressed air in a reservoir for supply to the engine during increased engine load operating conditions and replenishing the air in response to pressure dropping below a nominal threshold; and increasing the pressure beyond the nominal threshold in response to increased temperature of the stored air in the reservoir even when operating conditions include decreased engine load, and purging the increased temperature stored air to bring pressure back down toward the nominal threshold. In one example, increasing pressure to the reservoir may include supplying compressed air from an air suspension system. In one example, increasing pressure to the reservoir may include supplying compressed air from an air compressor separate from an engine turbocharger compressor. In one example, the method may include, in response to a vehicle operator tip-in during the increasing of the pressure beyond the nominal threshold, simultaneously supplying stored compressed air to the engine while replenishing the air.

A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

Aspects of the present invention relate to a controller (104) and method (400) for controlling operation of an internal combustion engine (101). The controller (104) is configured to: receive a first request signal indicative of a request to stop fuel being supplied to the engine (101), and cause an intake valve (301) of a cylinder (103) of the internal combustion engine (101) to remain closed during the current revolution of the internal combustion engine (101) and revolutions of the internal combustion engine (101) immediately following the current revolution of the internal combustion engine (101) in dependence on at least one of: the intake valve (301) being closed at the time of receiving the first request signal; or a next opening of the intake valve having not been scheduled. The controller (104) is also configured to cause injection of fuel into the cylinder (103) and subsequently cause the intake valve (301) to remain closed during revolutions of the internal combustion engine (101) immediately following a next closing of the intake valve (301), in dependence on at least one of: the intake valve (301) being open at the time of receiving the first request signal; and a next opening of the intake valve (301) having already been scheduled at the time of receiving the first request signal and said next opening of the intake valve (301) is to be performed.

A controller may identify an indication to initiate an engine braking procedure associated with an engine of a machine. The controller may obtain, based on identifying the indication to initiate the engine braking procedure, information relating to a requested amount of engine braking power of the engine. The controller may cause one or more components of a variable geometry turbocharger (VGT) of the engine to adjust, and a throttle valve of the engine to adjust, based on the information relating to the requested amount of engine braking power of the engine.

A controller for a hybrid vehicle controls a first motor generator and a second motor generator such that electric power input to a battery does not exceed an input upper limit value and electric power output from the battery does not exceed an output upper limit value. The controller executes motoring to rotate an output shaft using the first motor generator with combustion operation of an engine stopped, thereby causing a braking force generated by friction of the engine to act on a driven wheel. The controller executes a valve-opening limitation process that limits an increase in a throttle open degree in correspondence with the input upper limit value upon issuance of an increase request for the throttle open degree that is not based on an operation of requesting a change in the braking force performed by a driver during the execution of the motoring.

A controller, in shifting the state of the EGR system from the EGR operating state to the EGR non-operating state at the time of performing the deceleration of the vehicle, calculates a provisional EGR ratio that is a provisional value of the current EGR ratio, estimates the provisional EGR ratio as the actual EGR ratio when a fore-and-aft differential pressure of the EGR valve is equal to or more than a predetermined value, performs correction to make the provisional EGR ratio smaller, and estimates the corrected provisional EGR ratio as the actual EGR ratio when the fore-and-aft differential pressure of the EGR valve is less than the predetermined value.

Methods and systems are provided for engine braking in a vehicle. In one example, a method may include, in response to an engine braking request: deactivating fueling to at least one engine cylinder, decreasing an effective flow area of a turbine inlet of a variable geometry turbocharger (VGT), and adjusting an intake valve of the at least one engine cylinder based on a requested braking torque of the engine braking request and the effective flow area of the turbine inlet. In this way, increased exhaust backpressure may be generated to increase engine pumping losses while the intake valve adjustment increases in-cylinder pumping losses, thereby increasing an amount of engine braking torque.

A control system and method relating to operation of an internal combustion engine, particularly an engine for powering an unmanned aerial vehicle. The engine has a combustion chamber and a throttle for regulating fluid flow to the combustion chamber, the throttle being operable under the control of an electronic control unit. With the control system and method there are first and second modes optionally available for operation of the engine. In the first mode the engine is operable at a throttle setting set by a request from a first remote controller (e.g. a ground-based controller) via a second on-board controller. In the second mode the engine is operable at a prescribed minimum throttle setting asserted by the electronic control unit which limits the authority of the on-board controller. The engine is caused to operate in the second mode if a particular throttle setting determined from a request of the remote controller is less than the prescribed minimum throttle setting.

A method for operating an engine during a fuel cut-off mode is disclosed. The method may adjust exhaust valve opening timing and exhaust valve lift of one or more cylinders to heat air flowing through the one or more cylinders so that a temperature of an after treatment device may be maintained or increased.

Methods and systems are provided for improving fuel economy and reducing undesired emissions. In one example, a method may include in response to an engine speed being within a first threshold speed of an engine idle speed during a speed reduction request with engine cylinders unfueled, maintaining the cylinders unfueled, and controlling the engine to a desired stopping position responsive to the engine speed being greater than a second threshold speed lower than the idle speed. In this way, fuel usage and emissions may be reduced and engine restart requests may be conducted at least in part via vehicle inertia.