The Taipei MRT （Metropolitan Rapid Transit） system has been operated since 1996. Facing the challenge of safety and sustainability of MRT, it is urgent to develop a structural inspection strategy and maintenance sys...The Taipei MRT （Metropolitan Rapid Transit） system has been operated since 1996. Facing the challenge of safety and sustainability of MRT, it is urgent to develop a structural inspection strategy and maintenance system based on the concept of life cycle management. In the mean while, BIM （Building Information Modeling） has become an emerging technology in the architecture and construction industries. BIM utilizes the 3D （3 Dimensions） CAD objects to simulate the real word building elements and with the ability to maintain life cycle information for a building. BIM is an ideal tool and platform for developing an inspection and maintenance system. The goal of this research is to establish a MRT structural inspection system concept based on BIM and life cycle management. In this study, a BIM model of shield tunnel was established to demonstrate the integration of 3D CAD with inspection records. A MRT structural maintenance database, which includes structural deterioration types, inspection records, and repair methods, was designed to interact with the BIM. An inspection prototype system was designed and implemented to perform the MRT structural inspection. The proposed system was designed with mobile-side and server-side systems. The mobile-side system was designed to perform on mobile devices such as tablet computer or smart phones with the ability to mark defects on BIM, as well as to fill in inspection sheets and photos; the server-side system can assign inspection tasks, maintains all inspection records, automatically output inspection reports, and analyze the database to prioritize all maintenance tasks.展开更多
In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection a...In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection are the full-field strain measurement with the required precision and on-site measurement ability. The digital correlation method （DCM）, a new optical deformation measurement tool, can satisfy all of the requirements for structure inspection. A smoothing algorithm which can greatly improve the strain measurement precision, and a 3-D DCM have been developed in this paper. For verifying this improvement, a comparison of strain measurements by computer-simulated speckle images has been carried out. Additionally, three structure inspection examples that cover typical materials and structure styles are presented： the interface shear stress distribution for reinforced concrete piles bedded on rock, the 3-D strain distribution of a composite vessel structure, and stresses in a hookup that connects two steel bridge structures. All the examples show that the new structural inspection tool is exemplary and illustrates the obvious advantages of this optical non-destructive technique.展开更多
Catastrophic natural disasters like earthquakes can cause infrastructure damage.Emer-gency response agencies need to assess damage precisely while repeating this process for infrastructures with different shapes and t...Catastrophic natural disasters like earthquakes can cause infrastructure damage.Emer-gency response agencies need to assess damage precisely while repeating this process for infrastructures with different shapes and types.The authors aim for an autonomous Unmanned Aerial Vehicle(UAV)platform equipped with a 3D LiDAR sensor to comprehensively and accurately scan the infrastructure and map it with a predefined resolution r.During the inspection,the UAV needs to decide on the Next Best View(NBV)position to maximize the gathered information while avoiding collision at high speed.The authors propose solving this problem by implementing a hierarchical closed‐loop control system consisting of a global planner and a local planner.The global NBV planner decides the general UAV direction based on a history of measurements from the LiDAR sensor,and the local planner considers the UAV dynamics and enables the UAV to fly at high speed with the latest LiDAR measurements.The proposed system is vali-dated through the Regional Scale Autonomous Swarm Damage Assessment simulator,which is built by the authors.Through extensive testing in three unique and highly constrained infrastructure environments,the autonomous UAV inspection system suc-cessfully explored and mapped the infrastructures,demonstrating its versatility and applicability across various shapes of infrastructure.展开更多
文摘The Taipei MRT （Metropolitan Rapid Transit） system has been operated since 1996. Facing the challenge of safety and sustainability of MRT, it is urgent to develop a structural inspection strategy and maintenance system based on the concept of life cycle management. In the mean while, BIM （Building Information Modeling） has become an emerging technology in the architecture and construction industries. BIM utilizes the 3D （3 Dimensions） CAD objects to simulate the real word building elements and with the ability to maintain life cycle information for a building. BIM is an ideal tool and platform for developing an inspection and maintenance system. The goal of this research is to establish a MRT structural inspection system concept based on BIM and life cycle management. In this study, a BIM model of shield tunnel was established to demonstrate the integration of 3D CAD with inspection records. A MRT structural maintenance database, which includes structural deterioration types, inspection records, and repair methods, was designed to interact with the BIM. An inspection prototype system was designed and implemented to perform the MRT structural inspection. The proposed system was designed with mobile-side and server-side systems. The mobile-side system was designed to perform on mobile devices such as tablet computer or smart phones with the ability to mark defects on BIM, as well as to fill in inspection sheets and photos; the server-side system can assign inspection tasks, maintains all inspection records, automatically output inspection reports, and analyze the database to prioritize all maintenance tasks.
文摘In structure inspections, applications of optical techniques are rare, but the advantages of a noncontact, full field technique using a simple apparatus are attractive. The main requirements for structure inspection are the full-field strain measurement with the required precision and on-site measurement ability. The digital correlation method （DCM）, a new optical deformation measurement tool, can satisfy all of the requirements for structure inspection. A smoothing algorithm which can greatly improve the strain measurement precision, and a 3-D DCM have been developed in this paper. For verifying this improvement, a comparison of strain measurements by computer-simulated speckle images has been carried out. Additionally, three structure inspection examples that cover typical materials and structure styles are presented： the interface shear stress distribution for reinforced concrete piles bedded on rock, the 3-D strain distribution of a composite vessel structure, and stresses in a hookup that connects two steel bridge structures. All the examples show that the new structural inspection tool is exemplary and illustrates the obvious advantages of this optical non-destructive technique.
文摘Catastrophic natural disasters like earthquakes can cause infrastructure damage.Emer-gency response agencies need to assess damage precisely while repeating this process for infrastructures with different shapes and types.The authors aim for an autonomous Unmanned Aerial Vehicle(UAV)platform equipped with a 3D LiDAR sensor to comprehensively and accurately scan the infrastructure and map it with a predefined resolution r.During the inspection,the UAV needs to decide on the Next Best View(NBV)position to maximize the gathered information while avoiding collision at high speed.The authors propose solving this problem by implementing a hierarchical closed‐loop control system consisting of a global planner and a local planner.The global NBV planner decides the general UAV direction based on a history of measurements from the LiDAR sensor,and the local planner considers the UAV dynamics and enables the UAV to fly at high speed with the latest LiDAR measurements.The proposed system is vali-dated through the Regional Scale Autonomous Swarm Damage Assessment simulator,which is built by the authors.Through extensive testing in three unique and highly constrained infrastructure environments,the autonomous UAV inspection system suc-cessfully explored and mapped the infrastructures,demonstrating its versatility and applicability across various shapes of infrastructure.
