Coal seam discontinuity sensor and method for coal mining apparatus

摘要

A continuous mining apparatus such as a coal milling or shearing machine includes sensors mounted on the machine frame or on the cutter bits, including an accelerometer and one or more strain gauges, for sensing vibrations and stresses exerted on the cutter bits during operation of the machine. A signal conditioning and amplification circuit provides an audio and/or visual display indicating when the cutter is moving outside of the coal seam and/or is cutting along a cleat or other joint to improve excavation rates while maintaining or lowering stress levels on the cutter bits. The display enables the machine operator to keep from penetrating the roof or floor of the coal seam and to position the cutter to take advantage of natural fracture lines in the seam. The frequency spectrum of the sensor signals is determined to distinguish vibrations caused by bit interaction with the material being cut.