Reducing measurement noise in rock bolts detecting

For nonstationary signal in rock bolts detecting, an effective denoise method based on Hilbert-Huang transform is presented, and a few key questions using HHT method are discussed. At first, by empirical mode decomposition (EMD) algorithm, a sum of intrinsic mode functions (IMF) are got, and then, the IMF coefficients in useful signal dominative layer are proceeded using soft threshold method, at last, those IMF coefficients are reconstructed. Compared with the traditional wavelet transform, the HHT method is better to remove measurement noise.