关键词: 超声频率跟踪, 增量PD, 模糊控制, 频率搜索, 换能器

Abstract: In order to avoid the problems of transducer heating and low efficiency caused by transducer detuning, a fuzzy PD ultrasonic frequency tracking algorithm was proposed. The idea of fuzzy control was applied to fuzzy PD ultrasonic frequency tracking algorithm. The exponential method was used to set the parameters of the PD controller in real time to achieve fast and accurate tracking of the resonance frequency. The input of the fuzzy control was the phase difference and the rate of change of the phase difference. The fuzzy controller recognized the current state of the transducer according to preset rules, and set the parameters of the incremental PD controller exponentially. The driving frequency was the result of incremental PD adjustment. Simulation experiments show that the frequency search algorithm can start from any frequency domain and complete the search of the resonance frequency of any ultrasonic transducer in 30 steps. The algorithm is compared with algorithms such as dichotomy and PD variable step size to verify its superiority in search accuracy and search speed. It is suitable for the search of the resonant frequency of the transducer and the design of the full frequency domain ultrasonic power supply.

Key words: ultrasonic frequency tracking, incremental PD, fuzzy control, frequency search, transducer