Research on the Frequency Tracking in Rotary Ultrasonic Machining

According to the characteristics of rotary ultrasonic machining, the paper designs rotary ultrasonic power matching circuits. It presents compound frequency tracking method that utilizing Phase-Locked Loop (PLL) on accurate frequency tracking and maximum current method on rough frequency tracking. A control strategy of frequency tracking based on adjusting matching inductance and driving frequency was described. The experimental results verify the proposed compound frequency tracking method is feasible and effective which eliminates temperature, load changed on the effect of the transducer.