Control device

A control device that controls a variable valve mechanism of an internal combustion engine based on a crank angle signal and a cam angle signal, the control device comprising:

• an operation angle calculation unit that:
• i) calculates an initial cam angle from an interval between a cam angle measurement reference position in a cam angle measurement range and an initial cam angle signal detection position at an initial position of the variable valve mechanism, ii) calculates an operation cam angle from an interval between the cam angle measurement reference position in the cam angle measurement range and an operation cam angle signal detection position at an operation position of the variable valve mechanism, and iii) calculates an operation angle of the variable valve mechanism from a difference between the initial cam angle and the operation cam angle;
• and
• a cam angle excess determination unit that determines whether the operation cam angle signal detection position has moved to another cam angle measurement range adjacent to the cam angle measurement range beyond the cam angle measurement reference position by an operation of the variable valve mechanism, wherein
• when the cam angle excess determination unit determines that the operation cam angle signal detection position has moved to another cam angle measurement range adjacent to the cam angle measurement range beyond the cam angle measurement reference position, the operation angle calculation unit calculates the operation angle based on the initial cam angle at the initial position of the variable valve mechanism and the operation cam angle of the another cam angle measurement range at an operation position of the variable valve mechanism;
• wherein the variable valve mechanism controls a camshaft of the internal combustion engine to a target angle based on the operation angle calculated by the operation angle calculation unit.