At UC Berkeley’s Richmond Field Station, our innovative smart pavement incorporates fiber optic sensing cables embedded within a 100-meter-long stretch of hot mix asphalt roadway. Extensive experiments were conducted to assess the capabilities of phase-coherent optical time domain reflectometry (φ-OTDR) in capturing continuous spatial and temporal information regarding activities occurring on the road surface. Diverse scenarios involving a pickup truck, runner, pedestrian, and dog were tested, with each entity traversing the road while φ-OTDR monitored dynamic strain measurements. To validate the measurements, optical frequency domain reflectometry (OFDR) was employed, demonstrating that φ-OTDR could accurately detect and differentiate each event based on spatiotemporal strain signals. Ongoing research aims to further explore φ-OTDR’s potential in enhancing future intelligent transportation systems (ITSs).
Figure: Schematic diagrams of the roadway events and waterfall visualization of φ-OTDR measurements
(Source: Hubbard, Peter G., Ruonan Ou, Tianchen Xu, Linqing Luo, Hayato Nonaka, Martin Karrenbach, and Kenichi Soga. “Road deformation monitoring and event detection using asphalt‐embedded distributed acoustic sensing (DAS).” Structural Control and Health Monitoring 29, no. 11 (2022): e3067.)
Collaborators: CITRIS
Researchers: Jaewon Saw, Kenichi Soga
Domains: Transportation Infrastructure
Capabilities: Field Sensing
Publication: TBA!