Shearer fault-crossing method integrating coal loss model and equipment spatial constraints

Existing methods for shearers to cross faults seldom account for spatial constraints on fully mechanized mining equipment with respect to the roof and floor and the working-face advance and cutting directions, or the amount of retained coal, resulting in low cutting efficiency, high coal loss, and poor economic benefits during fault crossing. To address this problem, a shearer fault-crossing method integrating a coal loss model and equipment spatial constraints was proposed. First, based on fault, coal-seam, and equipment parameters, a coal loss model for shearer fault crossing was developed that considered coal-seam thickness, fault throw, and equipment adjustment capability, providing an effective tool for accurately assessing coal loss. Then, according to the mining process requirements of a fully mechanized mining face, a spatial constraint model for fully mechanized mining equipment was established using the attitudes of the shearer, scraper conveyor, and hydraulic supports as constraints. Finally, based on the spatial constraint model for fully mechanized mining equipment and the coal loss model for fault crossing, floor cutting control points for shearer fault crossing were planned using the area control method, roof cutting control points were planned using a boundary-tracking algorithm, and anomalous points on the cutting path were corrected, with a high recovery rate, low rock-cutting rate, and high passability as the optimization objectives. A globally optimal autonomous cutting path for shearer fault crossing was then generated. Simulation results showed that, for the same coal-seam thickness and equipment parameters, a smaller fault throw and greater equipment adjustment capability corresponded to less coal loss and better passability. Field application verified that the proposed method could ensure safe shearer passage through a fault with relatively little coal loss.