Design Of Overload Vehicle Monitoring And Response System Based On DSP

The usage of road and bridge is increasing exponentially with the development of social economy. The overload vehicles are making much more damage to the road surface than the regular ones, which can cause premature fatigue of the road and bridge. Many roads and bridges are equipped with structure health monitoring system (SHM) to provide early-warning to these damage and evaluate the safety of road and bridge. However, because of the complex nature of SHM system, it’s expensive to manufacture, difficult to install and not well-suited for the regular bridges and roads. Based on this application principle, this paper designs a compact structure health monitoring system based on digital signal processor (DSP), which is highly integrated, low-power, easy to install and inexpensive to manufacture.The system will mainly use the dynamic real-time data collected from the sensors arrays imbedded under the surface of road and bridge, and combine with the current damage analysis to estimate the bearing capability of the road and bridge. The designed system is divided into sensor arrays, the charge amplifier module, the DSP processing unit, the alarm system for overload and the estimate for damage of the road and bridge structure. Sensor arrays include a method for laying sensors under the ground that can accurately identify vehicles, and monitor their weights in heavy traffic. Then, the signals coming from sensor arrays go through the charge amplifier. DSP processing unit will receive the amplified signals, estimate whether it is an overload signal or not, and convert analog variables into digital ones so that they are compatible with the back-end digital circuit for further processing. The system will also restrict certain vehicles that are overweight, including taking image sampling and sending off alarm for vehicles in violations, and transferring the collected pressure data to remote data center for further structure health monitoring analysis by rain-flow counting method.Experimental results show that the pressure monitoring error rate for vehicles in normal speed is3.8%～8.7%and the system can accurately monitor the real-time overload of road and bridge. Besides, the miniaturization structure of the system will also make it easy to manufacture and save the cost of structure health monitoring.