Full-Field Spatial-Temporal Deflection Measurement of Large Slender Ratio Structure Based on Slice Template Match Model

Sufficient amount of sensors in all structural components is prerequisite to get full-field temporal-spatial displacements and is essential for large scale structure health monitoring. In this paper geometric property and small deformation hypothesis in engineering mechanics are embodied as prior structural knowledge, and introduced into machine vision method of large structure deflection monitor. A lightweight algorithm, slice template matching model (STMM), is developed to obtain full-field temporal-spatial displacement of slender ratio structure by constructing a template match model in every pixel column of each image frame. Temporal-spatial deflection of composite box girder under moving model truck load is achieved by STMM in indoor experiment, and verified by theoretical deflection curve differential equation and laser ranger measurement. Results show that measurement error is not constant and varies with time and space, and brightness inconstancy is proved to be source of measurement error, and indicate STMM is a lightweight high precision method.