A method for operating a multi-cylinder internal combustion engine in which every active cylinder operates in a four-stroke mode and every deactivated cylinder filled with an approximately completed gas filling is compressed and expanded during the four-stroke operation of the activated cylinder. In a method in which excitations of a crankshaft speed are minimized, a limited number of even-numbered cylinders of a multi-cylinder internal combustion engine (2) having a maximum even number of cylinders (20, 21, 22, 23, 24, 25) are deactivated sequentially, the limited even number of cylinders being smaller than the maximum even number of cylinders (20, 21, 22, 23, 24, 25) of the multi-cylinder internal combustion engine (2).

A method of operating a split intake D-EGR (dedicated exhaust gas recirculation) engine having at least one D-EGR cylinder and a number of non-EGR cylinders. If the engine is in a low load operating condition, either of two cylinder deactivation modes may be performed. In first cylinder deactivation mode, the D-EGR cylinder(s) are deactivated by disabling fuel delivery to the D-EGR cylinder(s), closing a D-EGR throttle, closing a D-EGR valve, and operating a three-way valve on the main exhaust line such that no exhaust from the D-EGR cylinder(s) is exhausted. In a second cylinder deactivation mode, the non-EGR cylinders are deactivated by disabling fuel delivery to the non-EGR cylinders, opening the D-EGR throttle, closing the D-EGR valve, and operating the three-way valve such that no exhaust from the main cylinders is exhausted.

A control apparatus is applied to an internal combustion engine that is capable of implementing reduced-cylinder operation and all-cylinder operation. When the internal combustion engine is stopped during implementation of reduced-cylinder operation, and then the internal combustion engine is restarted in reduced-cylinder operation with the same cylinders as idling cylinders, the initial crank angle when cranking starts is controlled so that the position of the piston of at least one among the idling cylinders is in the vicinity of its top dead center.

Systems and methods are provided for an engine wherein one group of cylinders is active and a second group of cylinders is switchable, such that under low loads the second group of cylinders is deactivated, and under high loads the second group of cylinders is activated. Following deactivation of the second group of cylinders a throttling element in an intake line for the second group of cylinders is gradually closed. The closing of the throttling element may reduce pumping losses and thus increase engine efficiency.

A method is provided for controlling an internal combustion engine including at least one first cylinder and at least one second cylinder with respective reciprocating pistons, each of the first and second cylinders being arranged to receive air from a fresh air intake arrangement, to receive fuel, and to provide repetitive combustions by means of the received air and fuel, the method including receiving in the first cylinder air from the fresh air intake arrangement, expelling from the first cylinder gases in the form of the air received in the first cylinder or gases including at least a portion of the air received in the first cylinder, guiding to the second cylinder gases expelled from the first cylinder, injecting fuel into the second cylinder so as to provide repetitive combustions with air in the gases guided from the first cylinder to the second cylinder, and, while guiding to the second cylinder gases expelled from the first cylinder, throttling or inhibiting the supply to the second cylinder of air from the fresh air intake arrangement, wherein guiding to the second cylinder gases expelled from the first cylinder includes guiding to the second cylinder all gases expelled from the first cylinder.

Methods and systems are provided for compression heating of air. In one example, a method may include, during an engine start and prior to a first combustion event, deactivating cylinder exhaust valves while spinning the engine electrically and unfueled until a threshold intake air temperature is reached, and alternately activating and deactivating the exhaust valves of one or more cylinders to maintain the intake air temperature above the threshold temperature after the first combustion event. In this way, a temperature of an air charge may be increased, resulting in increased fuel economy and decreased vehicle emissions.

A cylinder control module: selects one of N predetermined cylinder activation/deactivation patterns as a desired cylinder activation/deactivation pattern for cylinders of an engine, wherein N is an integer greater than two; and activates and deactivates opening of intake and exhaust valves of first and second ones of the cylinders that are to be activated based on the desired cylinder activation/deactivation pattern, respectively. A fuel control module provides fuel to the first ones of the cylinders and disables fueling to the second ones of the cylinders. The cylinder control module further: determines M possible ones of the N cylinder activation/deactivation patterns, wherein M is an integer greater than or equal to one; selectively compares the M possible cylinder activation/deactivation patterns with the desired cylinder activation/deactivation pattern; and selectively updates the desired cylinder activation/deactivation pattern to one of the M possible cylinder activation/deactivation patterns.

A process of controlling operation in a multi-cylinder engine either during start of operation or low-load conditions is disclosed. The process may include skipping a supply of fuel in a first set of cylinders of the multi-cylinder engine for a pre-defined number of multiple working cycles. The process may further include supplying fuel-air mixture to a second set of cylinders of the multi-cylinder engine for the pre-defined number of multiple working cycles. The process may also include executing combustion of the fuel-air mixture supplied to the second set of cylinders for the pre-defined number of multiple working cycles. In addition the process may include either changing a selection of cylinders included in the first set of cylinders and the second set of cylinders respectively, or switching the supply of fuel, after the pre-defined number of multiple working cycles, from the second set of cylinders to the first set of cylinders.

An internal combustion engine including a combustion chamber; a compressed gas valve wherein the compressed gas valve is arranged to enable compressed gas to be extracted from the internal combustion engine and used to provide power for mechanical functions: and a controller, wherein the controller is configured to receive a signal indicative of the configuration of the internal combustion engine and cause the compressed gas valve to be opened in response to a signal indicating at least one of that the internal combustion engine is decelerating and a throttle is closed to enable compressed gas to be extracted from the internal combustion engine via the compressed gas valve.

A process of controlling operation in a multi-cylinder engine either during start of operation or low-load conditions is disclosed. The process may include skipping a supply of fuel in a first set of cylinders of the multi-cylinder engine for a pre-defined number of multiple working cycles. The process may further include supplying fuel-air mixture to a second set of cylinders of the multi-cylinder engine for the pre-defined number of multiple working cycles. The process may also include executing combustion of the fuel-air mixture supplied to the second set of cylinders for the pre-defined number of multiple working cycles. In addition the process may include either changing a selection of cylinders included in the first set of cylinders and the second set of cylinders respectively, or switching the supply of fuel, after the pre-defined number of multiple working cycles, from the second set of cylinders to the first set of cylinders.