Path Planning for Open−Pit Mine Blasthole Inspection Robots Based on Safety−Embedded SA and QSF−Safe RRT*

Blast hole inspection is a critical process ensuring blasting quality, rock fragmentation effect and on−site operational safety in open−pit mines. Conventional inspection tasks are predominantly completed manually, suffering from low operation efficiency, high labor intensity and prominent safety risks for field workers on steep bench slopes. With the rapid development of robotics and intelligent mining technology, deploying autonomous inspection robots has become an important technical trend. However, integrating robotic systems with the complex terrain of blasting areas while avoiding hazards such as terrain−induced rollover and blast hole falling remains a key challenge. To address this issue, this paper proposed a path planning method for blast hole inspection robots based on Simulated Annealing (SA) and the QSF−Safe RRT* algorithm.First, a multi−dimensional traversability safety cost function for the inspection area was constructed by combining rigid blast hole safety distances with local terrain features including slope and surface roughness, embedding robot operation safety constraints at the source of path planning to avoid the defects of traditional post−hoc safety verification. Second, a safety−constrained SA algorithm was adopted to optimize the global inspection sequence of observation points, transforming the multi−point traversal task into a safety−constrained Traveling Salesman Problem (TSP) to balance path length and safety risk, and effectively improve planning efficiency in complex terrain environments. Third, a safety−prioritized QSF−Safe RRT* algorithm was developed, with terrain safety verification based on quadratic surface fitting embedded into the full process of node sampling and tree expansion. Cubic B−spline curves were further applied to smooth the initially planned trajectories to satisfy the robot’s kinematic constraints.Simulation results show that under typical working conditions represented by dense quincunx blast hole layouts, the generated global paths achieve a 100% compliance rate for both blast hole safety distance and terrain traversability safety cost, with zero hazardous zone crossings throughout the whole path. Compared with greedy TSP combined with traditional RRT and RRT* algorithms, the proposed method reduces the global path length by 28.66% and 10.68% respectively in complex scenarios, and path smoothness is significantly improved. This study provides reliable technical support for the safe navigation of inspection robots in the complex terrain of open−pit blasting areas.