Research On Multi-sensor Weighing In Motion System Research

Since joining the world trade organization,China has met its rapid development in its national economy.As the road transport is acting as a booster of economic development,the country has invested more and more effort in its highway construction,and China's highway traffic mileage has reached the top of the world.Along with the rapid development of highway traffic,the problem of vehicle overload is becoming more and more serious,which will not only threaten the traffic security,but also cause damages to the traffic infrastructures.In order to combat the highway overloading activities,highway management department and traffic law enforcement department urgently need a device that can implement real-time monitoring of the axle-load of the vehicles on the road.The traditional vehicle axle-load measurement system has many problems including slow traffic speed,discontinuous weighing.To solve the above problems,this paper develops a PVDF-based dynamic weighing system,which is portable and cheap,providing a measurement for relevant departments to monitor the highway and enforce law on the highway.The project is funded by the science and technology project of Guangxi Zhuang Autonomous RegionMain works of this paper:1.investigating in depth the Chinese and foreign literatures,as well as the research status of dynamic weighing system,the problems and shortages in the existing dynamic weighing systems are summarized and analyzed.Based on the experimental conditions,the PVDF piezoelectric film axle sensor is chose as the sensor of the dynamic weighing system designed in this paper.2.For selecting the measuring circuit of the dynamic weighing system,voltage amplifier-type,current-type and charge amplifier-type measuring circuits are compared in this paper,and the charge amplifier-type is chose finally.In order to analyze the impact of dynamic characteristics stemming from the measuring system on the measurement of the force signal of tires,the force signal of tire is firstly simplified to a non-periodic trapezoidal wave signal,and is analyzed in frequency domain.Then the measurement system model is built,and the process of tire force passing the measurement system is stimulated by using relevant Labview system simulation modules.By doing so,the impact of vehicle speed on the dynamic weighing system can be analyzed.Finally,hammer experiment is designed in the lab to verify the model built above.3.A dynamic weighing system based on Labview and NI data acquisition card is designed in this paper.In the mean time,field experiment is designed in this paper to verify the feasibility of the dynamic weighing system designed,and establish the model of impact of vehicle speed on weighting process.Axle-load measuring model of each sensor is built by using the data of weighing system,and finally the axle-load of a vehicle is predicted by using the model established.4.Targeting at the problem that the vibration of vehicle will cause error in axle-load measurement,measuring data from the four weighing sensors are processed by fusion processing via the method of multiple sensors weighted fusion.In evaluating the accuracy of measurement result,measurement confidence is induced in this paper to evaluate the axle?load measurement result.The result shows that after a fusion processing,the confidence of axle-load measurement result within the range of[-10%,10%]is higher than the confidence of each sensor before processed by fusion processing.