The measurement of ship deformation has been a difficult problem for the global ship building industry and navigation field research.So far,an effective and proven method for measuring 3D position and attitude deforma...The measurement of ship deformation has been a difficult problem for the global ship building industry and navigation field research.So far,an effective and proven method for measuring 3D position and attitude deformation remains unavailable.This article proposes an innovative pose-relay videometrics measurement system for ship deformation on the basis of primary research and experimental validation.The system offers solutions to the important technical problems such as infrared marker manufacture,high-precision detection and multi-camera synchronization and control.Sea trials were carried out,and reasonable,long-term,and continuous 3D data of position and attitude deformations between a given deck point and the ship reference,and between the ship's head and the stern were acquired for the first time.The experiments have highlighted the considerable applicability of the proposed method of deformation measurement and long-term monitoring of ships and similar large structures.展开更多
When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those...When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those instruments in unstable positions will cause measurement errors or even the complete failure of long-term subsidence surveillance. In this paper, the innovative concept and its method of "displacement-relay videometrics" are proposed. With the method, a double-headed camera is designed, and two constraints, the "fixation constraint" and the "homologous constraint", are established to construct the displacement-relay measurement equations, which can concurrently give the subsidence of the points to be measured and the positions where the cameras are fixed. The method and its measurement system are thus capable of automatically measuring the surface subsidence under the condition that the cameras are mounted on unstable locations over long durations. Therefore, the method has the broad prospect of undertaking automatic, long-term and continuous measurement for surface subsidence in engineering projects such as railroad beds, bridges and the ground beds of tall buildings. The proposed method opens a new area that cameras can be mounted on unstable platform to make high accuracy measurements, which is of great significance for applications.展开更多
基金supported by the National Natural Science Foundation of China (10727202)
文摘The measurement of ship deformation has been a difficult problem for the global ship building industry and navigation field research.So far,an effective and proven method for measuring 3D position and attitude deformation remains unavailable.This article proposes an innovative pose-relay videometrics measurement system for ship deformation on the basis of primary research and experimental validation.The system offers solutions to the important technical problems such as infrared marker manufacture,high-precision detection and multi-camera synchronization and control.Sea trials were carried out,and reasonable,long-term,and continuous 3D data of position and attitude deformations between a given deck point and the ship reference,and between the ship's head and the stern were acquired for the first time.The experiments have highlighted the considerable applicability of the proposed method of deformation measurement and long-term monitoring of ships and similar large structures.
基金supported by the National Natural Science Foundation of China(Grant Nos.11332012 and 11172323)
文摘When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those instruments in unstable positions will cause measurement errors or even the complete failure of long-term subsidence surveillance. In this paper, the innovative concept and its method of "displacement-relay videometrics" are proposed. With the method, a double-headed camera is designed, and two constraints, the "fixation constraint" and the "homologous constraint", are established to construct the displacement-relay measurement equations, which can concurrently give the subsidence of the points to be measured and the positions where the cameras are fixed. The method and its measurement system are thus capable of automatically measuring the surface subsidence under the condition that the cameras are mounted on unstable locations over long durations. Therefore, the method has the broad prospect of undertaking automatic, long-term and continuous measurement for surface subsidence in engineering projects such as railroad beds, bridges and the ground beds of tall buildings. The proposed method opens a new area that cameras can be mounted on unstable platform to make high accuracy measurements, which is of great significance for applications.
