Pose graph SLAM-based displacement estimation for a multiple structural displacement monitoring system

In this paper, we employ the graph SLAM (Simultaneous Localization And Mapping) technique for displacement estimation for a multiple structural displacement monitoring system. A visually servoed paired structured light system (ViSP) was recently proposed as a novel estimation method of the 6-DOF (Degree-Of-Freedom) relative displacement in civil structures. To apply the ViSP to massive structures, multiple ViSP modules should be installed in a cascaded manner. In this configuration, the estimation errors are propagated through the ViSP modules. To address this problem, a displacement estimation error back-propagation (DEEP) method was proposed. However, the DEEP method has some disadvantages. To overcome the limitation of the DEEP method, a pose graph SLAM-based displacement estimation method is proposed. Simulations and experiments are conducted to validate the performance of the proposed method. The results show that the proposed method reduces the propagation errors in comparison with a previous work.