Low cost vision-based systems using smartphones for measuring deformation in structures for condition monitoring and asset management

Asset management is an important area in civil engineering. Monitoring deformations and movements of structures is an essential tool for the asset management and condition monitoring. Currently, a range of technologies such as contact (e.g. strain gauges and displacement sensors) and non-contact sensors (e.g. lasers, radars and cameras) is available for monitoring structural response. However, there is a need for low cost systems, which could be used for real life situations and laboratory environments (for teaching and research). This paper presents a novel approach of using smartphones to monitor movements in structures. The low-cost and easy to use hardware (i.e. smartphone) is readily available for the majority of people. The idea is that a smartphone camera is used to monitor specific markers (points of interest) on a structure. Movements of the markers can be obtained and calibrated for accurate movements of the structure. This paper presents results obtained from both lab structures and a full-scale bridge. Results show that the technology is a simple, low-cost and provides indicative and at the same time accurate information about structural response.