Intelligent optimization and control technology for drilling process of coal mine tunnels

The harsh environment for drilling construction of coal mine tunnel, complex coal seam structure and complicated operation procedures can cause low drilling efficiency and high drilling cost. For this reason, it is imperative to carry out studies on the optimization and control technology for the drilling process of coal mine tunnel. Herein, study was conducted from intelligent identification of lithology of coal-bearing formation, intelligent optimization of drilling parameters and their intelligent control, focusing on the key technology for control of drilling process of coal mine tunnel. First, in order to accurately determine the type of coal-bearing formation, an intelligent identification model of coal-bearing formation lithology based on BP-Adaboost was established. Then, an intelligent optimization model based on mechanical specific energy and drilling speed was established under different condition of coal-bearing formations, to provide the driller with the reference values of optimal feed pressure and rotational speed. Next, a fuzzy PID-based feed pressure control strategy was proposed to realize the effective control of feed pressure. Finally, field test was implemented in a coal mine in Huainan with the intelligent drilling system of drill rig for coal mine tunnel. The test results indicate that: the identification accuracy of the proposed intelligent identification model for coal-bearing formation lithology is up to 96.75%. The intelligent optimization method improves the drilling rate significantly and reduces the mechanical specific energy, thereby improving the drilling efficiency and reducing the drilling cost. The feed pressure control strategy could stabilize the feed pressure near the optimal value, reduce the overshoot of the feed system while speeding up the system response, thereby ensuring the dynamic response of the feed pressure smoother. Intelligent optimization and control technology for drilling process of coal mine tunnel can effectively guarantee the safe and efficient operation of the drilling process and promote the intelligent development of the drilling technology for coal mine tunnel.