Research On Focal Region Measurement Technology Of Focused Transducer

Focused transducers in the field of acoustics are widely used in various industrial fields because of their acoustic advantages.At present,the research on the characteristics of the focused transducer mainly focuses on the sound field,and the measurement of the sound field is an important step to evaluate the performance of the transducer.In order to solve the problem of low efficiency in measuring the sound field of focused ultrasonic transducers using point-by-point scanning of mechanical motion mechanisms,the elliptical and rectangular contour transducers are studied in this paper,a new focused transducer focal region measurement system is designed and developed by combining the non-contact fast detection characteristics of machine vision with the flexibility and controllability of the six-degree-of-freedom manipulator.The specific content of the study is as follows:(1)Based on the analysis of sound field propagation theory,the focal field parameters of the focused transducer are given,and the overall measurement scheme is designed.The nine-point calibration method is used to establish the transform relation between the pixel coordinate system and the base coordinate system of the manipulator,and the fast focus location of the transducer is realized by combining the ellipse detection algorithm based on edge connection and rectangle detection algorithm.(2)In this paper,the acoustic lens focused transducer and concave spherical self focused transducer are simulated by using COMSOL finite element method.Based on the characteristics of the simulated sound field,the measurement path of the transducer is planned as a concentric circle with the center of focus and the interval step of different decibel of sound pressure,which improves the detection efficiency and precision.(3)A set of focused transducer sound field measurement system based on manipulator is designed and built.Two different focused transducers are tested by this system,the experimental results are compared with the results of traditional mechanical structure measurement and the simulation results of the focal region parameters,and the uncertainty of the voltage at the focal point is analyzed.The experimental results show that the focus location error is within a reasonable range,and the detection efficiency is improved with the accuracy of the measurement results guaranteed The feasibility and effectiveness of the sound field measurement system studied in this paper are verified by comparing the focal field parameters.