When obtain piston position signal from Crankshaft, Top Dead Center Sensor and Crankshaft position Sensor tend to be integrative in structure.

TDC (top dead center) - the position of the crank and piston when the piston is farther away from the crankshaft.

Further, the piston is operated at the top dead center position and in the resonance state under all load conditions, thereby further increasing operation frequency.