Research on panoramic camera system for geotechnical borehole monitoring

To achieve short-range, dynamic panoramic imaging and high-resolution visual inspection of local areas of interest (ROIs) of the inner wall of a long borehole, a panoramic camera system for rock borehole condition detection is developed. The system is capable of generating a 360° panoramic image from a single frame. This is achieved by leveraging the small focal length and the exceptionally large angle of a single fisheye lens. The system's side incorporates a high-definition camera module, enabling the system to perform high-resolution inspection of any targeted region through rotation. Furthermore, the primary structure of the camera system incorporates a self-balanced design to maintain the coherence between the optical axis and the target center. The wheel-coded counting method effectively compensates for the axial orientation information of the system. By integrating it with the overlapping field of view from adjacent frames in panoramic imaging, it becomes feasible to capture panoramic images of the inner wall of long channels. Experimental results demonstrate that the system can achieve high-resolution panoramic imaging over short distances with long channels. With the assistance of the self-balanced structure and axial orientation module, the system provides a foundation for panoramic unwrapping of long channels. It further offers valuable quantitative data for intelligent evaluation of geotechnical holes.