Ceiling inspections present challenges due to limited accessibility and structural constraints. To ease the burden on security personnel, who would otherwise need to manually disassemble, inspect, and restore ceiling components, this study proposes a robotic system for detecting hazardous objects within ceiling environments. The proposed system features several key innovations: a hollow-structured track mechanism designed to reduce vibrations from jolting while traversing structural beams and to improve localization accuracy. We optimized the robot’s mass distribution and required drive torque through dynamic simulations to ensure stable mobility in confined ceiling spaces. For effective hazardous object detection, we developed a YOLOv8-Seg-based background learning algorithm that suppresses ceiling-structure patterns, allowing for the identification of unknown objects without prior class-specific training. Additionally, we introduced a frame-based filtering algorithm to enhance detection reliability by reducing false positives caused by motion blur during movement. The system's effectiveness was validated through experiments conducted in a ceiling-structured testbed, demonstrating its capability for accurate hazardous object detection under realistic operating conditions.

Strain wave gears are widely used as reducers in robots, including collaborative and industrial robots. As a key component, they play a crucial role in determining overall robot performance. To enhance their effectiveness, various studies have focused on directly measuring the performance of assemblies or predicting the performance of individual components through analysis. However, there is a notable lack of research that experimentally measures and compares the physical properties of the circular spline, flexspline, and wave generator—the primary elements of strain wave gears. In this paper, we developed equipment to measure the radial stiffness of the flexspline, one of the key components, and validated its reliability through preliminary experiments. Furthermore, we measured and compared the radial stiffness of flexsplines produced by three different manufacturers. These findings are expected to provide valuable insights for improving the performance of strain wave gears and advancing robotics technology.