Patent ID: 8190317

Claim:
A mode change control method of a hybrid vehicle, the method comprising: (a) comparing a transmission input speed with an engine idle speed, when a mode change from EV to HEV is required; (b) when it is determined that the transmission input speed is less than the engine idle speed, open-loop controlling, by a controller, a pressure of a clutch so that an optimal engine torque of an operation point determination circuit is transferred through the clutch after engine complete explosion and engine speed increase control occur, wherein the engine speed is increased up to the engine idle speed, which is a target engine speed for slip, and (c) when it is determined that the transmission input speed is higher than the engine idle speed, feedback controlling, by the controller, the clutch pressure so that a delta RPM follows a predetermined target delta RPM profile after engine complete explosion and the engine speed is increased until the delta RPM reaches a slip start delta RPM; and (d) applying a maximum clutch pressure, when the delta RPM, which is a difference between the engine speed and a motor speed, is reduced below a predetermined synchronization reference value until a predetermined reference time elapses, thus completing the EV to HEV mode change, wherein the predetermined synchronization reference value is a threshold value which is used to determine that speeds of both sides of the clutch have been synchronized and the predetermined reference time is a time threshold value for a predetermined delay after applying the maximum clutch pressure.