Network Matching Against Frequency Drift for Ultrasonic Drills: Method and Experiment

In deep space exploration, ultrasonic drill is an effective tool for asteroid landing anchoring. As the drive time grows, the resonance frequency of the ultrasonic drill piezoelectric transducer is offset, which leads to a serious degradation of the matched ultrasonic drill speed. In order to solve the problem that the performance of the matched transducer decays with the change of resonance frequency, this article proposes a design method of matching circuit that minimizes the output change for all variations of the resonance frequency of the transducer. Considering the ultrasonic drill working characteristics, the drilling speed is strongly correlated with the current, active power, and drilling pressure of the transducer by using principal component analysis and gray relational analysis. Current and active power models with the variable resonance frequency parameters ${p_{l}}$ and ${p_{c}}$ as variables were established based on LC-type topology. The models are applied to ultrasonic drill to obtain three matching schemes, and then analyze the variation of current and active power when the load fluctuates and the driving frequency has deviation. After experiments, it is proved that when the matching capacitance is 1.3$\times 10^{-8}$ F and the matching inductance is 1.44$\times 10^{-3}$ H, the drilling speed is fast and does not decay with frequency.