Study On FBG Dynamic Weighing Sensor

The development of communication and transportation industry has undoubtedly played an active role in the construction of national economy. However, the overloading of trucking vehicles remains incessant in despite of repeated prohibition. So that it becomes more and more important to reinforce control over road transportation. Dynamic weighing, i.e. weighing the vehicle on its moving state, with the characteristic of higher efficiency and time-saving, avoids the disturbance to the traffic in the weighing process, as compared with static weighing. The study of dynamic weighing technology is of economic significance and social value in assurance of appropriate use of the roads.As the development of intelligent materials, especially the fiber sensor represented by fiber grating, it provides new approaches and prosperous future for the research of weighing system. Fiber Bragg Grating sensor, which uses the property that the Bragg wavelength is sensitive to strain and temperature, is a new kind of fiber optic sensor. The FBG sensor has some special characteristics such as immune to environment interference, integrating sensing and transmission, simple structure and ease of use, which can greatly improve (he safety, reliability and sensitivity of products. So FBG sensing technology will have widely applicable perspective in vehicle weighing system.This thesis, focusing on the problem of traditional vehicle weighing sensors, introduces a FBG weighing sensor based on equal intensity beam. It firstly analyzes strain-model of FBG and gives an experiment that verifies the linear characteristic of strain to wavelength change. On the basis of the above we design the dynamic weighing sensor through the analysis of force on weighing sensor and make experiment both static and dynamic. By arithmetic average filtering of pulse anti-interference to experimental results, it concludes that average error of dynamic measurement is 2.96% when vehicle speed is below 5km/h. The result indicates that the designing of weighing sensor has fairly good accuracy of measurement, while noises should be further solved.In summary, in our study we have investigated the manufacture of WIM sensor by use of fiber Bragg grating in both theoretical and technological approaches. According to the experimental results, we can conclude that the sensor we design is successful. This WIM sensor model will have great potential for future applications in real technology market.