THE EFFECT OF LONGITUDINAL INCLINATION IN AUTOMATIC CONTROLLED SHEARER WORKFACES.

In underground coal mining the shearer is a commonly used extraction machine in longwall workfaces. Beside the manual control of the shearer by an operator, today the memory cut, but also other automation methods can be used for cutting drum height adjustment. The result of the cut of both, the lower and the upper, cutting drums is the generated face opening at one position of the longwall workface. For a straight seam these automation procedures will work adequately and the generated face opening will be constant, but without correction they won't work properly if longitudinal seam inclination changes. Because of the dimension of the shearer, there is a distance of some meters between the cutting drum and the contact to the face conveyor of the shearer body. So the longitudinal inclination at the position of the shearer body will influence the cut, which is executed some meters away. This can cause safety critical situations, in case of inclination change, because the cutting drums will leave coal in the face and cut surrounding rock, without adaption of the cutting drum height. The focus of this paper will be to illustrate the aforementioned problem for cutting drum height adjustment, using the memory cut or other automation methods, if seam inclination changes in longitudinal direction of the face. Therefore, some simulation results will be shown for different ground situations of a seam. Additionally, a control algorithm will be tested to show the advantages of the cutting drum height adjustment by involving the measured floor inclination and the seam trend. [ABSTRACT FROM AUTHOR]