The present invention relates to a control device and a control method for a variable valve timing mechanism that changes a valve timing by adjusting a rotational speed of a motor. The control device detects a phase angle RA1 based on an output of a crank angle sensor and an output of a cam angle sensor and calculates a change amount RA of a rotational phase based on a difference between a rotation amount of a sprocket and a rotation amount of the motor. The control device stops calculating change amount RA when a failure occurs in a motor rotation angle sensor. When a failure occurs in one of the crank angle sensor or the cam angle sensor, the control device stops calculating phase angle RA1 and calculates change amount RA using a normal one of the sensors and the motor rotation angle sensor.

Various methods for operating a camshaft are provided. In one example, a method of operating a camshaft comprises: adjusting the camshaft based on a desired camshaft position, the desired camshaft position determined based on a camshaft position indicated by a camshaft sensor and a camshaft position indicated by a camshaft actuator.

A control method and apparatus for a variable engine valve operating control mechanisms which move the engine valves to a safe lift/timing position with respect to a piston to minimize the potential for valve to piston contact during valve surge. At least one engine operating conditions is selected and provided with a threshold triggering a control to move the valves to a safe position in a calibrated, predictive manner in advance of any potential valve to piston contact. The control method and apparatus can be integrated into the existing engine control and variable valve operating control mechanism.

A continuously variable valve timing (CVVT) control device is provided. The CVVT control device includes an engine controlling unit (ECU) configured to output an actual phase angle and a target phase angle of an intake valve or an exhaust valve. The CVVT control device further includes an intellectual motor controller configured to receive the actual phase angle and the target phase angle from the ECU through digital communication in a vehicle. A driving current is generated for adjusting an output torque of a motor based on a phase deviation between the received actual phase angle and target phase angle.