Design of Ultrasonic Guided Wave Pipeline Non-Destructive Testing System Based on Adaptive Wavelet Threshold Denoising

Abstract

Guided wave ultrasonic testing (GWUT) within the realm of pipeline inspection is an efficacious approach; however, current GWUT systems are characterized by high costs and power consumption, and their detection results are significantly susceptible to noise interference. Addressing these issues, this study introduces a GWUT system predicated on adaptive wavelet threshold denoising, centered around a low-power main controller, achieving cost-effective and low-power-consumption pipeline non-destructive testing (NDT) with clear results. The system employs an STM32 as the main controller and utilizes direct digital frequency synthesis (DDS) technology to generate ultrasonic excitation signals. These signals, after power amplifier processing, ensure high-stability output for the driving signal. In conjunction with the signal acquisition module, digital filtering of the collected signals is executed via the host computer. Empirical validation has demonstrated that the system can achieve an output amplitude of up to 90 Vpp within an excitation frequency range of 20 kHz–400 kHz, directly driving piezoelectric transducers. The optimal threshold is identified using the butterfly optimization algorithm, enabling the wavelet threshold function to adaptively denoise the echo signals, thereby significantly enhancing the capability to identify pipeline damage.