One-way ViSP (visually servoed Paired structured light) for 6-DOF structural displacement measurement

Abstract

Structural health monitoring (SHM) of civil infrastructures has gained great attention since it is directly related to public safety. To estimate structural displacement, which is considered as one of important categories of SHM, aoneway type vision and laser-based 6-DOF displacement measurement system (oneway ViSP) is proposed. The system is composed of a transmitter with two laser pointers, a 1-D laser range finder (LRF), and a 2-DOF manipulator; and a receiver with a camera and a screen. The lasers and LRF project their parallel beams to the screen and the camera attached to the screen captures the image of the screen. The manipulator controls poses of the lasers and LRF for projected laser beams to be always inside the screen. By calculating positions of the laser beams and obtaining the distance from LRF, the relative displacement between two places can be estimated. The performance of the system has been verified from simulations.