Car Axle Load Dynamic Measurement System Design

We have extensively studied the present status of vehicles WIM at home and abroad and have systematically discussed the WEVI methods based on the dynamic axle load measurement.We have designed a bearing plate, selected the sensors, and built a new WEVI device which is simple, reasonable, easy to install and array round of distributed wheel load measurement units. After installing, we gave the WIM system static calibration.We have designed a number of simulant experiments based on single-round load measurement, researched the signal processing algorithms of WIM system, obtained effective curves of wheel load time and set up a mathematical model of the measuring system. Because the dynamic response of sensor system was unperfect, we have designed the project of dynamic compensation, derived algorithm of dynamic compensation and verified the validity of the method of compensation. After analyzing and comparing metrical results, we have found the greater the speed, the greater relative error of the WIM conclusions. We have summed up the impact of changing the vehicle wheel centre on measurement platform to weighing result and given several weighing result according to different locations.We have designed the integral hardware project of the dynamic axle load measurement system in light of the project's requirement, designed signal processing circuit of the resistance strain weighing transducer (including the amplifying circuit and the filter circuit), and designed the AD transforming circuit based on LTC1867 and the communication interface circuit of RS-232 between TMS320VC5416 and the computer.According to hardware circuit, we have designed software program of data acquisition, algorithm processing and serial communication. We have tested the hardware circuit and software program in the laboratory and found hardware circuit and software program could meet the basic system requirements.