Experimental study on fractal characteristics of load spectrum of shearer roller in different operating conditions

In order to study the load spectrum characteristics of shearer rollers under different operating conditions,the fractal box dimensions were used to characterize them.The curve of drum load spectrum under each working condition was detected by test and then processed by wavelet de-noising.Finally,the dimension of drum load spectrum box under different working conditions was calculated by MATLAB and the dimension of the box was analyzed.The results show that under the same hardness of coal and rock,as the traction speed increases,the dimensionality of the load spectrum box of straight-line cutting drum decreases gradually,that is,the fluctuation of drum load decreases gradually.When the hardness and traction speed of coal rock are equal.The straight line cutting and the bevel cutting have little effect on the dimensionality of the load spectrum box of the roller,which shows that the fluctuation of the roller load will not change violently and obviously under the two conditions.Under the same traction speed and cutting mode,With the increase of the Coal Rock Proton’s Coefficient,the dimensions of the drum load spectrum box decrease obviously,that is,the fluctuation of the drum load decreases gradually.