Research Of Weighing And Vehicle-Speed Measuring System By Using Composites Combined With FBG

With the high-speed development of the traffic, over-loading is coming from bad to worse. Over-loading not only destroys traffic infrastructures, but also causes traffic accidents frequently. Traditionally there is the kind of weight system: static weighting platform on pavement. Static weighting platform has the requirement of low vehicle speed. It also has low accuracy and is liable to miss measurement. It shows bad durability due to its complex structures. So, Weight-in-motion systems in the traffic system are becoming more and more important.In this paper, a new kind of smart composite material dynamic weighing system using the sensing properties of fiber bragg grating has been developed. The method of axes weight is applied. The main idea of smart complex material weight-in-motion systems is based on the principle that the deformation of weighing system can be gotten from the main beam with lie FBG strain sensors. The dynamic loads identification is to inversely resolve structural dynamic loads according to system dynamic character and actually measured power response, namely, the deformation of weighing system. Accordingly, the traffic weight can be gotten.Because of above idea, firstly, composite material have a lot of merits, such as light weight, high intensity, water-fast and environment-resistant, as the same time, fiber sensor are widely used for small volume, good sensitivity, electromagnetic interference-resistant, erodibility-resistant and good combination with composite material. So weighing system is designed for the features of rationality, simplicity, convenience and durability. Secondly, starting with the dynamic analysis of weighing system, the dynamic model of weighing structure is constructed. On the basis of theoretic analysis, the dynamic loads identification arithmetic is resolved according to actually measured power response of weighing system. Finally, the static and dynamic experiments of weighing system are carried. The static experimental results show that the value of the load have a linear correlation with the change of strain and the most strain of the structure satisfies the safeness of the structure and the synthesize demand of sensitivity on measurement and the weighing structure is design rationally. The static and dynamic experimental results prove that the dynamic loads identification arithmetic is logical. Moreover analyze the error and show the path of accuracy improvement.