Novel weigh-in-motion system based on FBGs

In this weigh-in-motion (WIM) research, a novel fiber Bragg grating (FBG)-based weigh-in-motion (WIM) system was introduced. The design derived from the idea using in-service bridge abutments as the weigh scale. The bridge beam was replaced by a piece of steel plate which supports the weight of the traveling vehicle. All weights would be finally transferred into the tubes where four FBGs were attached and could record the weight-induced strains by shifting their Bragg wavelengths. The system identification algorithm based on parameters estimation was initiated. Over 40-ton load had been applied on the system and the experimental results showed a good repeatability and linearity. The system resolution had been achieved as low as 10 kg. Compared with other designs of fiber-optic WIM systems, this design is easy and reliable.