A phaser which has three camshaft start positions at start-up during cranking before the engine can fire. By having three possible start positions of the phaser, there is an increase in flexibility of the cam position at startup during cranking. The three start positions can also be achieved in open loop, reducing the complexity of the control system needed at cranking.

A phaser which has three camshaft start positions at start-up during cranking before the engine can fire. By having three possible start positions of the phaser, there is an increase in flexibility of the cam position at startup during cranking. The three start positions can also be achieved in open loop, reducing the complexity of the control system needed at cranking.

A method for controlling intake and exhaust valves of an engine may include: determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, current opening and closing timings of the intake valve and/or exhaust valve based on the target opening duration of the valves; and advancing or retarding, by the intake and/or exhaust CVVD devices, the current opening timing of the intake and exhaust valves while simultaneously retarding or advancing the current closing timing of the intake and exhaust valve by a predetermined value based on the target opening duration.

A method for controlling intake and exhaust valves of an engine includes: Controlling opening and closing timings of the intake and exhaust valves by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT devices; determining, by a controller, target intake and exhaust opening durations of the intake and exhaust valves, and target opening and closing timings of the valves based on an engine load and an engine speed; modifying current intake and exhaust opening durations based on the target opening durations via an intake continuous variable valve duration (CVVD) device and an exhaust CVVD device; adjusting opening or closing timings of the valves to the target opening or closing timings of the valves while maintaining the modified opening durations of the valves.

A method for controlling intake and exhaust valves of an engine may include: determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, current opening and closing timings of the intake valve and/or exhaust valve based on the target opening duration of the valves; and advancing or retarding, by the intake and/or exhaust CVVD devices, the current opening timing of the intake and exhaust valves while simultaneously retarding or advancing the current closing timing of the intake and exhaust valve by a predetermined value based on the target opening duration.

A method for controlling intake and exhaust valves of an engine includes: Controlling opening and closing timings of the intake and exhaust valves by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT devices; determining, by a controller, target intake and exhaust opening durations of the intake and exhaust valves, and target opening and closing timings of the valves based on an engine load and an engine speed; modifying current intake and exhaust opening durations based on the target opening durations via an intake continuous variable valve duration (CVVD) device and an exhaust CVVD device; adjusting opening or closing timings of the valves to the target opening or closing timings of the valves while maintaining the modified opening durations of the valves.