Research on active roof control space of fully mechanized caving support based on motion posture perception

The fully mechanized top-coal caving support is a critical device that serves both as a support mechanism and an active means for top-coal caving in fully mechanized top-coal caving mining operations. Proactive engagement and reinforcement of the top-coal can effectively guide its intelligent and orderly fragmentation. To investigate the theory of active perturbation and control of the top-coal by the support system, as well as to clarify the dynamic interaction and support space between the fully mechanized top-coal caving support and the top-coal, a dynamic perception method has been proposed. This method aims to enhance the controllability of the top-coal fragmentation and caving process by accurately perceiving the relative spatial postures of various components and the absolute spatial position and orientation of the fully mechanized top-coal caving support. Firstly, utilizing the Denavit-Hartenberg (D-H) method, a mathematical model of the spatial posture of the fully mechanized top-coal caving support is established. Through this analysis, the coordinates of the support's canopy beam and top-coal caving mechanism in both the coordinate systems of each joint node and the body coordinate system are determined, thereby elucidating the relative postures and motion coupling relationships among the key components of the fully mechanized top-coal caving support. Building on this foundation, a global perception model for the fully mechanized top-coal caving working face is constructed, allowing for the derivation of absolute spatial position and orientation data of the support. Additionally, the influence of the dip angles of the working face roof and floor on the spatial support posture of the fully mechanized top-coal caving support is analyzed. Secondly, distribution models for the contact support space of the top beam and the support space of the coal caving mechanism in fully mechanized top-coal caving supports were developed and calculated. This process yielded the active regulation range of the fully mechanized top-coal caving support for managing the top-coal. Simultaneously, the Levenberg-Marquardt (L-M) optimization algorithm, initialized with preferred values, was employed to investigate the regulation method for achieving the optimal active contact posture of the support and determining the effective driving stroke of the upright post. Finally, a support posture data acquisition system was established. Utilizing the 7303 fully mechanized top-coal caving working face in Zhaolou Coal Mine, Heze City, Shandong Province, real-time spatial posture parameter data during the movement of the support were collected. By comparing the theoretically calculated data with the sensor-measured data, the feasibility and accuracy of the spatial position and orientation measurement method were validated. The results indicate that the coincidence rate between the Top beam posture calculated by this method and the sensor-measured results reaches 98.26%. This study provides a valuable research direction for further enhancing the spatial position and orientation perception technology of the support.