As for the problem of low accuracy of capacitive sensors on the non-contact vibration measurement of aero-engine rotor blades, the centroid extraction tip-timing authentication algorithm was proposed and a high-precision centroid extraction module was formed. The capacitive sensor and high-precision centroid extraction module were used on the core engine turbine blades to obtain the tip-timing signal and vibration results of the turbines. The results showed that the tip-timing signal of turbine rotor blades with capacitive sensor appeared groove phenomenon and the jam signal came out at high speed. The high-precision centroid extraction module can solve the problem and the vibration measurement accuracy can be improved. The research results will play an important role in engine and core engine turbine rotor blade non-contact measurement tests.
Liu et al. (Sun,) studied this question.