Research on load-bearing characteristics and adaptive support mechanism of intelligent solid backfilling support robot for coalmines

In order to meet the demand for improving the productivity and efficiency of solid backfilling mining technology and achieve the autonomous and efficient operation of backfilling support robots in intelligent filling working faces. In view of the particularity of the front - rear double - beam bearing of the backfilling support robot, the influence of the rear bearing beam on the front bearing beam is equivalent to the resultant force acting on the co - axial hinge point. Based on the instantaneous center method, the moment balance equations of the front and rear bearing beams are established, the force balance area is defined, and the relationship between the bearing capacity, the position of the acting point of the resultant external load and the bearing attitude is established. The kinematic analysis method of parallel robots is used to obtain the mapping relationship between the output load of the bearing beam and the load of the driving robotic arm. The structural stiffness matrix under different bearing postures is solved to obtain the vertical stiffness curves of the front and rear bearing beams. Multibody dynamics simulation software is used to establish the hydraulic and mechanical system models, and the direct roof is approximated by stiffness - damping springs. The interaction forces between the bearing beam of the robot and the direct roof in different stages are simulated through co - simulation. The results show that when the acting point of the resultant external load of the front and rear bearing beams is within the area of the front and rear support robotic arms and the co - axial hinge point, the bearing capacity of the robot is good. The position of the acting point of the resultant force of the rear bearing beam affects the bearing capacity of the front bearing beam and changes the working state of the balance robotic arm. For the front bearing beam, the magnitude of the external load and the position of the acting point of the resultant force can be solved based on the attitude parameters and the working resistance of the robotic arm, but the working resistance of the rear support robotic arm cannot directly solve the magnitude of the external load and the position of the acting point of the resultant force of the rear bearing beam. The stiffness curve is less affected by the attitude, with a large value near the co - axial hinge point and a sharp decrease away from it. The interaction force between the bearing beam and the direct roof is large near the co - axial hinge point and decreases sharply away from it, showing an “umbrella - tip” - shaped distribution, which is approximately similar to the vertical stiffness curve. The research results reveal the interaction relationship between the bearing beam of the backfilling support robot and the direct roof from the perspectives of moment balance, parallel robots, and structural stiffness, providing a theoretical basis and new research ideas and methods for the autonomous identification of bearing conditions and adaptive support of the robot. This is helpful to promote the intelligent upgrading of solid backfilling mining technology and is of great significance for improving mining efficiency and safety.