Piezoelectric Cable-based Vehicle Dynamic Weighing System Design

The program of a vehicle WIM with multi-strand piezoelectric cable was proposed and verified in this paper. The output signal waveform of the piezoelectric cable was studied in detail. The dynamic weighing plate with multi-strand piezoelectric cable that can be used conveniently was built.A large amount of dynamic load measurement experiments were completed.A suitable program was designed,which was used to reducing signal smooth noise,meanwhile a lot of experimental data available were obtained.Because the temperature has so great effect on the output of piezoelectric cable that the temperature compensation was designed. The model of the vehicle WIM was established by system identification based on experimental data, which was also demonstrated correctly through experiments. The influence of changing the vehicle wheel centre on measurement platform on weighing result was summed up.In order to achieve engineering application, hardware circuit of vehicle WIM was developed. The design of the charge amplifier circuit was based on the op-amp AD823,as well as the analog filter circuit based on CY8C27243 and the analog to digital conversion circuit based on TLV1571 and the asynchronous serial communication circuits between the DSP and PC were all contained.According to hardware circuit, the software program of CY8C27243 and data acquisition and signal processing and serial communication based on DSP was layouted.For the convenience of the user to read data, data acquisition interface was compiled by Visual Basic. Experimental test was carried out, and the debugging results turned out that the hardware and software could meet the requirements of the system.