The Measuring System For The Dynamic Deflection Of Bridge Based On DSP

The deflection is closely connected with bridge performance such as the carrying capacity and the ability to resist natural disasters. So studying the measuring method and system of the bridge deflection became very important to evaluate the stability, the life-time and the ability to resist natural disasters of the bridge.This paper proposed a system measuring the bridge deflection by using inertial electro magnetic sensor to collection the vibration signal. Firstly, the principle of the inertial electro magnetic sensor and the bridge vibration characteristic under load were analyzed. The performance of different sensor were also analyzed to give reference for selecting different sensor. A FIR low pass filter, which can improve the accuracy of signal processing , was designed by MATLAB. With the dynamic collecting experimental platform , the forced vibration of simply supported beam is experimented to simulate the shock response of the bridge caused by vehicle. This scheme was compared with traditional method and the error was analyzed.In this system TMS320LF2407A DSP chip was used as its core processing unit, and a system measuring deflection online for long-time was proposed which can transfer the analogue signals to digital signals . Computer can receive the deflection data from DSP by RS232, display it by graphic and digital and save it to index . The thesis analyzes in detail the design scheme and parameter setting of the electronic components ,and proposes a anti-interference scheme by software aimed at the system stability. The system was developed and debugged, the prototype was built, which has reference value to the actual measurement engineering.