System and method for controlling of valve timing of continuous variable valve duration engine

A system for controlling valve timing of a continuous variable valve duration engine, comprising:

• a data detector for detecting data related to a running state of a vehicle;
• a camshaft position sensor for detecting a position of a camshaft;
• an intake continuous variable valve duration (CVVD) device for controlling an opening time of an intake valve of the engine;
• an exhaust two stage variable valve duration (VVD) device for controlling an opening time of an exhaust valve of the engine by one of and short duration and a long duration;
• an intake continuous variable valve timing (CVVT) device for controlling an opening and closing timing of the intake valve of the engine;
• an exhaust continuous variable valve timing (CVVT) device for controlling an opening and closing timing of the exhaust valve of the engine;
• and
• a controller configured to classify a plurality of control regions depending on an engine speed and an engine load based on signals from the data detector and the camshaft position sensor and to control the intake CVVD device, the exhaust two stage VVD device, the intake CVVT device and the exhaust CVVT according to the control region,
• wherein the controller applies a maximum duration to the intake valve and the long duration to the exhaust valve and limits an overlap in a first control region, applies a maximum duration to the intake valve and the long duration to the exhaust valve and adjusts the overlap according to the engine load in a second control region, applies the long duration to the exhaust valve, fixes an exhaust valve open (EVO) timing and an exhaust valve close (EVC) timing, and advances an intake valve close (IVC) timing according to an increase of the engine load in a third control region, controls a wide open throttle valve (WOT) and applies the short duration to the exhaust valve in a fourth control region, and controls the wide open throttle valve (WOT), applies the long duration to the exhaust valve and delays the intake valve close (IVC) timing according to an increase of the engine speed in a fifth control region.