Background: The load characteristics of pick cutting coal seam with coal-rock interface
were studied by Time-frequency method in this paper. The common signal processing schemes were
compared, and the suitable test load EMD (Empirical Mode Decomposition) empirical mode decomposition
scheme for signal decomposition and denoising was selected.
Objective: The cutting load power spectra were obtained and the cutting load 3D (three dimensional)
combined amplitude, time frequency, spectrum and marginal spectrum were obtained by Hilbert Huang
Methods: The analysis by 3D combined amplitude, time frequency, spectrum and marginal spectrum
shows that it becomes one of the main cutting bands of coal rock interface in 15Hz frequency band,
which corresponds to the theoretical analysis of the load fluctuations in drum bands. Because the parameters
related to the single cutting rotation frequency are affected by the interface change. The more
obvious frequency components are near 45Hz and 75Hz which are due to the frequency doubling of the
frequency variation with the interface load, which should be related to the frequency of the included
angle with the pick speed.
Results: It can be seen from the power spectrum analysis of roller cutting test that the main frequency
distribution is generated by the crossover motion parameters and the caving effect of the picking and
the role of coal and rock, and the material parameters of the cutting object are related.
Conclusion: The coal load amplitude transition will appear with coal seams cut into the rock formation
in the coal seam, which is consistent with the previous theoretical analysis and load characteristics
analysis. The blasting of coal and rock has a great relationship with the homogeneity of coal and rock
material itself, the material with the uniformity index is more stable, while the material load with
smaller uniformity index fluctuates violently.