Application of Sensor Technology for Coal Mining
For roadway drivage in their mines RAG Deutsche Steinkohle AG uses, next to the conventional blasting, roadheaders, too. These are automated to such extent that after entering the cross section the heading face in front of the roadheader can be excavated without manual control of the cutter boom. In a further step of automation the cross section shall follow the alternating level of the coal seam along drifts. To do so, the course of the boundary layer between coal and surrounding rock needs to be gathered by sensors.
In the research and development project »Intelligent Mining Roadheaders« Fraunhofer IML investigated sensor systems suited for this task, in particular the technical feasibility for underground application. The mechanic and climate exposure and the requirements on fire damp according to the ATEX guidelines needed to be taken into account.
Using the kinematics of the machine, Fraunhofer IML developed a 3D laser scanner system scanning the heading face within the infrared spectrum. The measured readings deliver a 3D image of the heading face. An integrated signal processor calculates the coordinates of the coal seam and transfers them to the control of the machine, which determines the ideal value for the next step of excavation. For the evaluation of the archived image of the heading face with respect to geology and mine surveying, Fraunhofer IML developed moreover some software for visualization.
The first intelligent roadheaders equipped with this sensor system are tested in operation at the Prosper-Haniel colliery in Bottrop.