Comparison of Single-Camera-Based Depth Estimation Technology for Digital Twin Model Synchronization of Underground Utility Tunnels

Digital twin technology can be used for disaster safety management of underground utility tunnels, which are social infrastructures. To verify its efficiency in an tunnel, it must implemented and monitored the real world. Therefore, state information about object position world, change upon movement, should correspondingly reflected digital model. Underground tunnels through closed circuit television (CCTV) cameras because main infrastructure facilities installed a long narrow form, limits access to them. synchronization model tunnel requires method identifying location CCTV camera. This study compares DenseDepth transfer learning coordinate system conversion floor plan projection estimate depth using single camera tunnel. The plane showed error 0.23 m 1.5 within 50 range. 1 3 m; therefore, was considered unsuitable distance estimation. smaller even at longer than method. more suitable estimation