The Research Of Distributed Bridge Data Acquisition System

Bridge is an important part of the transport system, ensuring the safety of bridge structures is extremely important. At present, the monitoring of most bridges is mainly by periodical manual examination. However, this measure has some limitations such as poor real-time,inaccurate,partial monitoring and working with intensity. Taking advantage of modern communication technology to make a real-time monitoring and intelligent assessment and the essential maintenance is indispensable to assess the life of bridge, which provides a scientific method to the maintenance, repair and management decision-making of the bridge. In the future, a bridge healthy monitoring systems will become the new trend between large-scale bridge security systems.Bridge healthy monitoring system is generally consisted of two sub-systems which are data acquisition sub-system and security assessment systems of the structure health, and the data acquisition sub-system is the basis of the whole monitoring system. Whether the bridge healthy monitoring system can make an exact assessment to the bridge structures health, whether it can provide a scientific method to the bridge management and repair depends on whether the data acquisition sub-system can acquire the structure features information which is accurate, reliable, representational and accurately reflects the status of bridge.A bridge data acquisition distributed system is concerned in this paper, which can largely solve the problems in anciently bridge monitoring. The paper firstly analyses the background and its significance, then the whole project of the system design is concerned, in the end, this paper mainly research the carrying out of the bridge data acquisition distributed healthy monitoring system based on CAN bus. The system mainly researches the composing of the system and emphasizes on its carrying out of hardware and software.The main content of this paper is the depth research to the carrying out of the hardware and software of the system. And the design of data acquisition node based on CAN bus is the emphasis of this paper. With the characteristics of less demanding on the hardware in the distributed systems, this paper uses AT89C52 as the main control chip which with better compatibility, SJA1000 is used as the CAN bus controller which is manufactured by Philips Corporation, the PCA82C250 is used as the CAN bus driver, TLC2543 is used as the A/D conversion. The signal is isolated by optocoupler circuit. The paper has completed the initialization of CAN bus, the sending and receiving of the messages in software design etc. The hardware and software design of the industry computer adapter card is also concerned in the paper. PCI bus protocol is used in the adapter cards which is good performance and fast transfer rate.The bridge data acquisition distributed system puts the modern industrial bus and the bridge healthy monitoring together organically which is the highlight of this paper. The system is practical, not only can be used in the bridge data acquisition system, but also with a certain reference value in the other industrial site with complex environment.