Development Of Vehicle Dynamic Weighing System Based On Piezoelectric Sensor

In recent years,with the continuous development of China’s social economy,China’s highway transportation volume ranks in the forefront of the world.With the rapid development of the transportation industry,the phenomenon of overloading is becoming more and more serious.Vehicle overloading will not only cause air pollution,but also damage the road structure,damage public facilities,and cause all kinds of road traffic safety problems.This paper designs a vehicle dynamic weighing system based on piezoelectric sensor,which can realize the accurate measurement of vehicle dynamic axle load and provide technical support for highway overweight treatment.This paper first introduces the harm of overload phenomenon,analyzes the research progress of vehicle dynamic weighing at home and abroad,and introduces the working principle and characteristics of bending sensor,capacitance sensor,optical fiber sensor,piezoelectric ceramic sensor,PVDF piezoelectric film sensor and piezoelectric quartz sensor commonly used in dynamic weighing system at home and abroad,The advantages and disadvantages of each sensor are analyzed.Secondly,according to the American ASTM e1318 standard,European standard and China’s JJG907-2006 "dynamic highway vehicle automatic weighing instrument"verification regulation requirements,this paper formulates the functional requirements and technical indicators of dynamic vehicle weighing system.On the basis of weighing the cost and accuracy requirements,this paper proposes a method of measuring vehicle axle load based on piezoelectric quartz sensor and PVDF piezoelectric film sensor.Thirdly,the hardware and software of the dynamic vehicle weighing system are designed.The sensor signal is converted into voltage signal through the processing circuit of piezoelectric quartz sensor and PVDF piezoelectric film sensor,and the 16 bit high-precision acquisition chip is used to realize analog-to-digital conversion;Two axle load calculation methods are proposed to improve robustness and weighing accuracy;Develop application program to obtain axle load,vehicle speed,wheelbase,axle offset and other parameters.A data display platform integrating data receiving,calculation,display and management is designed.At last,the changing rule of the output characteristic of the sensor is studied by experiment;Simulation test is used to improve the function of software and hardware and test the stability of the system;In the actual road,we use a variety of types of vehicles to test,and evaluate the function,accuracy and reliability of the system.The test results show that the vehicle dynamic weighing system designed in this paper meets the design requirements.