Research status and prospects of robotic technology for secondary breakage of oversized ore and rock in underground stopes

With the continuous increase in mining depth and production intensity in underground mines, the generation of oversized ore and rock in stopes has become a critical factor constraining ore-drawing efficiency, equipment safety, and production continuity. At present, secondary breakage is mainly performed by blasting, mechanical impact, or static cracking. However, personnel are generally required to enter stopes or work in close proximity during drilling, charging, and breakage operations, resulting in prolonged exposure to hazardous conditions such as roof falls and rib spalling, fly rock, high noise levels, and toxic and harmful gases, thereby imposing considerable pressure on operational safety. To reduce personnel exposure to these hazards, the integration of robotic technologies with static cracking agents represents a promising direction for secondary breakage. Focusing on the requirements for automated charging and autonomous navigation of the secondary breakage robot of oversized ore and rock in stopes, this paper reviews representative underground charging robot systems developed in China and abroad and summarizes their functional characteristics and major limitations. A comprehensive analysis indicates that existing studies primarily focus on borehole localization and alignment based on two-dimensional visual information, while providing insufficient support for high-precision perception of three-dimensional borehole poses and closed-loop charging control. At the key-technology level, this paper reviews methodological frameworks for visual borehole recognition, three-dimensional borehole localization, borehole orientation perception, map construction, equipment localization, navigation path planning, and robotic-arm charging trajectory planning. The applicability of these methods is further analyzed under challenging underground conditions characterized by dust, low illumination, occlusion, and confined operating spaces. To improve the perception accuracy and automation level of secondary breakage robot of oversized ore and rock in stopes, future research should strengthen the perception of actual borehole poses and enhance the adaptability of algorithms and sensors throughout the operational process to stope environments.