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编码激励技术是提高超声穿透能力和分辨率的有效手段。为分析岩石特性对编码信号脉冲压缩性能的影响,通过数值模拟以及不同岩石的超声检测实验,研究并比较了几类编码信号的检测效果。结果表明幅度加权线性调频信号(TLFM)调制的Barker码信号(BTL)受到的信噪比损失低于正弦调制Barker码信号(BS),而分辨率损失要低于TLFM信号。实验结果验证了编码激励技术的有效性,为岩石超声检测中编码参数的设置提供了依据。
Coded excitation technique is an effective means to improve the penetration and resolution of ultrasound. In order to analyze the influence of rock characteristics on the pulse compression performance of coded signals, the detection effects of several types of coded signals are studied and compared by numerical simulation and ultrasonic testing of different rock. The results show that the signal loss of Barker code signal (BTL) modulated by amplitude-weighted chirp signal (TLFM) is lower than that of sinusoidally modulated Barker code signal (BS), while the resolution loss is lower than that of TLFM signal. The experimental results verify the effectiveness of the coding excitation technique and provide the basis for setting the coding parameters in rock ultrasonic testing.