Geometric parameter optimization of ultrasonic transducers for online thickness measurement of cable insulation based on DPSM and TOPSIS

To address the low amplitude and signal-to-noise ratio (SNR) of the echo signal during ultrasonic online detection of the insulation layer of large-curvature vibration cables, a quantitative optimisation method for the geometric parameters of ultrasonic transducer is proposed to optimally match the ultrasonic transducer and signal. The optimisation problem of the geometric parameters of the ultrasonic transducer was formulated according to cable vibration characteristics. Considering the signal performance of transducer and cost, a decision criterion including four indicators was proposed to optimise ultrasonic transducers, such as average amplitude. And the distributed point source method (DPSM) was used to quantitatively calculate the performance indicators. The technology for order preference by similarity to ideal solution (TOPSIS) with multiple weights was used to select the optimal geometric parameter scheme of the transducer. The experiments showed that the proposed method achieved the quantitative optimisation of a specific cable ultrasonic transducer. The average amplitude of the selected ultrasonic transducer signal was increased by 112.02% compared to the empirical selection scheme, and it effectively reduced the influence of curvature and vibration on the amplitude of the reflected signal. This provides a novel strategy for the design optimisation of ultrasonic measurement systems in complex environments..