Convoluted Reciprocity and Other Methods for Vehicle Speed Estimation in Bridge Weigh-in-Motion Systems

Abstract

In bridge weigh-in-motion systems, the vehicle speed is a fundamental input parameter for the weighing algorithm. The speed is generally obtained by processing structural responses measured at different locations along the bridge length. For this purpose, the convoluted reciprocity relationship was derived and utilized as the basis for a novel speed estimation method. In addition, this document reviewed other existing methods, such as correlation or point load approximation methods, using exclusively measured strain signals from the soffit of a bridge. These methods were studied and compared with illustrative examples and parametric studies based on simulated vehicle–bridge interaction responses. As a result, this document proposed several new possibilities for speed estimation. Subsequently, these methods were validated empirically with responses from a scaled experiment. The results clearly showed that the new speed estimation strategies proposed in this work offer a significant improvement in accuracy compared to existing methods.