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 provided with a turbo charger, the system comprising:

• a data detector configured to detect data related to a running state of a vehicle;
• a camshaft position sensor configured to detect a position of a camshaft;
• an intake continuous variable valve timing (CVVT) device configured to control an opening timing of an intake valve of the engine;
• an exhaust continuous variable valve duration (CVVD) device configured to control an opening time of an exhaust valve of the engine;
• an exhaust continuous variable valve timing (CVVT) device configured to control an opening timing and an 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 camshaft position sensor, and configured to control the intake CVVT device, the exhaust CVVD device, and the exhaust CVVT device according to the plurality of the control regions,
• wherein the plurality of control regions comprises:
• a first control region determined by the controller when the engine load is less than a first predetermined load;
• a second control region determined by the controller when the engine load is greater than or equal to the first predetermined load and less than a second predetermined load;
• a third control region determined by the controller when the engine load is greater than or equal to the second predetermined load and less than a third predetermined load;
• a fourth control region determined by the controller when the engine load is greater than or equal to the second predetermined load and the engine speed is greater than or equal to a first predetermined speed and less than a second predetermined speed;
• a fifth control region determined by the controller when the engine load is greater than or equal to the third predetermined load and the engine speed is less than the first predetermined speed;
• and
• a sixth control region determined by the controller when the engine load is greater than or equal to the third predetermined load and the engine speed is greater than or equal to the second predetermined speed, and
• wherein the controller applies a maximum duration to the intake valve and controls a valve overlap by using the exhaust valve in the first control region, and the controller advances an intake valve closing (IVC) timing and applies the maximum duration to the exhaust valve in the second control region, advances the intake valve closing (IVC) timing and an exhaust valve closing (EVC) timing in the third control region, fixes an exhaust valve opening (EVO) timing and approaches the exhaust valve closing (EVC) timing to a top dead center in the fourth control region, controls a wide open throttle valve (WOT) and retards the exhaust valve opening (EVO) timing in the fifth control region, controls a wide open throttle valve (WOT), advances the exhaust valve opening (EVO) timing, and approaches the exhaust valve closing (EVC) timing to the top dead center in the sixth control region.