Automatic frequency tracking method of supersonic transducer and system thereof

Abstract

The invention relates to an automatic frequency tracking method and a system for an ultrasonic transducer. A direct digital frequency synthesizer is used as a signal source, wherein the direct digital frequency synthesizer can be an independent integrated chip and also be achieved by the method that a digital part of a DDS is integrated in a site programmable logical element FPGA and then a digital-analog converter is additionally added. The design of the invention adopts a frequency sweeping and tracking policy, and an automatic frequency controller achieved by the programmable element controls the output frequency of the DDS according to a feedback signal sampled from the self transducer end so as to achieve the full digitization automatic frequency tracking and ensure that the ultrasonic transducer work near a resonance point all the time to obtain the optimal efficiency. A phase comparator utilizes a trigger to give out the arriving time difference of two riser edge signals of twoinput signals I ph and V ph aiming to the sensitive characteristics of the riser edge signals, and the sequence of the riser edge signals of the two input signals I ph and V ph is given out by a Dirrect pin.

Description

technical field [0001] The invention relates to the field of ultrasonic transducers, in particular to an automatic frequency tracking method and system for ultrasonic transducers. Background technique [0002] A typical ultrasonic transducer has a high quality factor (Q value) and a steep resonance curve. Only when it works at its resonance frequency point can it have a large mechanical amplitude and high motor conversion efficiency. Therefore, the driving circuit of the ultrasonic transducer should be excited with its resonant frequency signal. [0003] However, the resonant frequencies of practical transducers are often discrete and varying. This is because: (1) the difference in materials and processes in the manufacturing process of the transducer; (2) the change of the load characteristics matched by the transducer; (3) the parameters of the transducer itself change with time and temperature during use. Wait for changes. Therefore, the driving circuit of the transduc...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to solve the problem that the transducer cannot fully release the power and the duty ratio of the phase comparator to the two input signals due to the low precision of the frequency tracking that exists in the automatic frequency tracking scheme using a phase-locked loop circuit A relatively demanding problem, thus providing an automatic frequency tracking method and system for ultrasonic transducers

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