A control system for a mining machine which moves in passes across a seam
to be mined using absolute coordinates is disclosed. The machine is
carried on rail and co-ordinates of the rail are measured along the length
of rail. The rail is then moved to a new position for a next pass, and the
distance of moving is determined from the co-ordinates previously
measured. By knowing the co-ordinates, the rail can be moved to assume a
desired profile, so that a desired profile of the seam can be achieved on
the next pass. Co-ordinates of the up and down movement of a shearing head
can also be measured and stored with the co-ordinates along the rail to
provide a profile of the seam being cut, and so that on a next pass the
intended position of the shearing head can be predicted and moved
accordingly.
