Field Validation of Flexure-Based Mobile Sensing Nodes on a Space Frame Bridge

Abstract

This research investigates the field validation of flexure-based mobile sensing nodes developed for structural health monitoring (SHM). Each mobile sensing node is a miniature robot that can carry sensors and automatically navigate on a steel structure. The flexible body design of the mobile sensing node allows it to negotiate with sharp corners on the structure. Multiple mobile nodes then form an organic mobile sensor network that can search for potential structural damage. Our previous research has investigated the performance of the mobile sensing nodes through laboratory experiments. The mobile sensor network was able to identify minor structural damage, illustrating a high sensitivity in damage detection that is enabled by the flexible deployment of the mobile sensing nodes. This paper extends the investigation into field study with a space frame bridge. Under wireless control command, multiple mobile and tetherless sensing nodes navigate autonomously to different sections of the steel bridge, for measuring structural vibrations at high spatial resolution. Using a small number of mobile sensing nodes, detailed modal characteristics of the bridge are identified.