Engine valve operation timing control apparatus

摘要

An engine valve operation timing control apparatus having a learning control function determines whether both of an actual phase difference angle and a target value between a crankshaft and a camshaft are almost constant for a predetermined time. When both of the actual phase difference angle and the target value become almost constant for the predetermined time, a control value is learned. A controller outputs the learned value to driving means to find a control value thereafter based on the learned value. As a result, the learning means learns the control value in correspondence with a rate of change of the actual phase difference angle and the control value found by the controller compensates for a disturbance factor. The learning operation is updated every time the actual phase difference angle and the target value converge to a constant value and is repeated when the convergence state continues.