An engine brake controller may obtain a performance characteristic of an engine. The engine brake controller may determine, based on the performance characteristic of the engine, that engine braking is enabled to control the engine. The engine brake controller may monitor a set of operating parameters of the engine. The engine brake controller may determine that operating values of the set of operating parameters satisfy corresponding thresholds of the set of operating parameters. The engine brake controller may determine, based on the operating values satisfying the corresponding thresholds, an engine braking configuration associated with activating engine braking of a set of cylinders of the engine. The set of cylinders may be a proper subset of a total quantity of cylinders of the engine. The engine brake controller may cause the engine braking to be applied to the set of cylinders to increase a temperature of exhaust gas from the engine.

A method of controlling CDA conversion may include determining whether CDA device is in CDA mode driving area according to obtained vehicle operation status signal; preparing, when CDA device is in CDA mode driving area, for operating in the CDA driving mode; performing conversion to CDA mode on each cylinder of the CDA device; and controlling, when CDA device is not in DA mode driving area, vehicle driving according to normal area operation map of the CDA device, wherein at performing of conversion to CDA mode on each cylinder, when converting mode of the CDA device from on-operation mode to an operation mode, after combustion is performed in selected cylinder, first exhaust valve maintains an operation state, and remaining exhaust valves and intake valves are converted to non-operation state to perform an exhaust anti-trap control.

An engine control method includes a step of setting combustion mode in which a first combustion mode in which a mixed gas is combusted by propagating flame or a second combustion mode in which the mixed gas is combusted by self-ignition is selected, a step of setting air-fuel ratio mode in which a lean first air-fuel ratio mode or a second air-fuel ratio mode equal to or richer than a theoretical air-fuel ratio is selected, a step of setting torque reduction in which a torque reduction amount by which a torque generated by an engine is reduced based on a steer angle of a steering wheel, and a suppressing step in which reducing the torque generated by the engine based on the torque reduction amount set in the step of setting torque reduction is suppressed.

A method of controlling a transmission includes determining if an internal combustion engine of the vehicle is currently operating with active fuel management, or if the internal combustion engine is currently operating without active fuel management. The vehicle controller further determines if a possible engine torque is equal to, greater than, or less than a required engine torque. The transmission is upshifted when the internal combustion engine is currently operating with active fuel management, and when the possible engine torque is equal to or greater than the required engine torque. When the possible engine torque is less than the required engine torque, active fuel management is exited so that the internal combustion engine is currently operating without active fuel management. When the internal combustion engine is currently operating without active fuel management, the vehicle controller upshifts the transmission from the current gear ratio to the higher gear ratio.

A variety of methods and arrangements are described for controlling transitions between firing fractions during skip fire operation of an engine in order to help reduce undesirable NVH consequences and otherwise smooth the transitions. In general, both feed forward and feedback control are utilized in the determination of the firing fractions during transitions such that the resulting changes in the firing fraction better track cylinder air charge changing dynamics associated with the transition.

A variety of methods and arrangements are described for managing transitions between operational states of an internal combustion engine during skip fire operation of the engine.

Methods and systems are provided for synergizing the benefits of a variable compression ratio engine in a hybrid vehicle system. A vehicle controller may hold the engine in a lower compression ratio during engine pull-ups and pull-downs, in particular when passing through a low speed region where compression bobbles can occur. During engine operation, in response to a change in driver demand, the controller may opt to switch the compression ratio or maintain a current compression ratio while smoothing a torque deficit using motor torque, the selection based on fuel economy.

Engine controllers and control schemes are provided for managing engine state transitions requiring increased compressor pressure ratios in turbocharged engines operating in a cylinder output level modulation mode (e.g., skip fire, multi-level skip fire, or firing level modulation modes). In some circumstances, turbo lag can be mitigated by initially transitioning the engine to an intermediate effective firing density that is higher than both the initial and target effective firing density to increase the flow of gases through the engine and the turbocharger while maintaining a compressor ratio the same as or close to the initial compressor pressure ratio. After reaching a point where the desired torque is actually generated at the intermediate effective firing density, the operational effective firing density is gradually reduced to the target effective firing density while increasing the operational compressor pressure ratio to the target compressor ratio.

An internal combustion engine is provided with a plurality of cylinders, air intake valves provided to each of the cylinders, and a variable valve actuation mechanism for varying the valve actuation of the air intake valves. A motor drives the variable valve actuation mechanism. A motor controller controls the motor. The internal combustion engine is capable of operating in a cylinder deactivation mode, in which the air intake valves of some of the cylinders are kept shut. When the internal combustion engine is reactivated from the cylinder deactivation mode, the motor controller executes an air intake amount correction process, in which the opening duration of the air intake valves is temporarily increased, thereby increasing the amount of air taken in by operating cylinder for which the air intake valves have been opened or closed even during the cylinder deactivation mode.

A vehicle and method for controlling a vehicle having a variable displacement engine with an auxiliary machine connected directly to the engine crankshaft and to an energy storage device includes switching from a cylinder disablement (VDE) mode to a normal mode when the torque demand and engine speed lie outside an outer range defined by a first threshold (T.sub.out), and switching from the normal mode to the VDE mode when the torque demand and engine speed lie within an inner range, which lies within the outer range and defined by a second threshold (T.sub.in). When operating in a band between the two thresholds, the auxiliary machine draws energy from the energy storage device and supplements the output torque from the engine if operating in the VDE mode, and derives torque from the engine crankshaft to recharge the energy storage device if operating in the normal mode.