Noncontact cable tension force estimation using an integrated vision and inertial measurement system

Abstract

In this study, a noncontact cable tension force estimation technique was developed using an integrated vision and inertial measurement system (VIS) installed at a reference point, and the movement of the VIS was explicitly considered. Cable displacement was first estimated by applying a proposed contour-based algorithm to the vision measurements. Thereafter, the movement of the VIS at the reference point was estimated from the inertial measurement system and was used to compensate the error in the previously estimated cable displacement. Finally, the cable tension force was estimated using the compensated cable displacement. The feasibility of the proposed technique was validated through a laboratory test on a full-scale pedestrian bridge cable and a field test on a single-pylon cable-stayed pedestrian bridge. Overall, the proposed technique estimated the cable tension forces reliably with less than 1.3% discrepancy compared to those estimated by accelerometers.