Acoustic tomography system for online monitoring of temperature fields

摘要

For online monitoring of complex temperature distributions, an acoustic tomography system based on sound travel-time measurement is developed. For coping with the reverberation phenomenon in actual measurement, an anti-reflection interference measurement method for sound travel-time is proposed based on cross-correlation and peak recognition. In view of the fact the pixel number provided by commonly used reconstruction algorithms, such as least-squares methods, is very limited, radial basis function approximation and regularisation technique are used, which leads to the pixel number of the reconstruction image increasing dramatically. Mixed programming with LabVIEW and MATLAB is used. Queue structure is adopted to make data acquiring program and data processing program parallel. Test results show that the system can run normally as designed. The measurement values of sound travel-time acquired by the proposed method are stable even in strong reflection interference. Test results show that the system can run normally as designed. The measurement values of sound travel-time acquired by the proposed method are stable even in strong reflection interference. The temperature fields reconstructed are coincided with actual fields, and correctly reflect the temperature changes in the measured area with the heater number, heater location and heating time.