Influence of parameter identification errors on weighing accuracy of classical B-WIM

ObjectiveEstablished bridge weigh-in-motion (B-WIM) algorithm usually requires parameters as inputs, e.g., vehicle speed and moment of vehicle entering and exiting bridge. However, these key parameters are often impossible to obtain accurately in complex real-world situations. Exploring the influence of these key parameters on vehicle weight identification accuracy can further improve the weighing accuracy of B-WIM.MethodBridge refined finite element model and vehicle dynamics model were established. The influencing factors were comprehensively considered, e.g., vehicle type, vehicle speed, and bridge type. This study analyzed the influence of recognition accuracy of vehicle speed and moment of vehicle entering and exiting bridge on the accuracy of classical B-WIM algorithm, i.e., Moses method and strain area method. Finally, the field tests were conducted on the expressway bridge.Result10% recognition error in vehicle speed leads to 15%-90% increase in the axle weight recognition error using Moses method; and 5%-10% increase in the gross weight error using strain area method. 0.01 s recognition error in moment of vehicle entering and exiting bridge leads to 1%-10% increase in the axle weight recognition error using Moses method; and the gross weight error using strain area method increases by no more than 0.5%. It is further found that the increase in vehicle speed, increase in axle quantity and decrease in wheelbase lead to the significant increase in axle weight recognition using Moses method. Therefore, the influence can be mitigated through speed-limiting and axle group equivalent identification strategies.ConclusionAs key parameters of B-WIM algorithm, the identification accuracy of vehicle speed and moment of vehicle entering and exiting bridge exerts the non-negligible influence on weighing precision. Optimizing these two parameters is an effective approach to enhancing the performance of B-WIM systems and ensuring the accuracy of weighing result.