Investigation on self-sensing monitoring and resonant control of ultrasonic vibration–assisted cutting

Review of the design of power ultrasonic generator for piezoelectric transducer

“…Usually, the pure PLL phase control tracking method is only used to track the local resonant frequency, but not suitable for large frequency range sweep tracking [15] , [174] , [179] . Other methods (including the maximum current method [182] , maximum power method [183] , self-sensing model method [184] , composite tracking method [106] , etc.) can usually perform both global sweep frequency tracking and local resonance frequency tracking.…”