A Long term monitoring system for vibration control of civil structures

The paper deals with the design and implementation of an innovative system for long term monitoring of civil structures. With reference to a multi point test site, with long term monitoring requests, two different systems have been developed and tested. The first one, based upon the use of analog sensors and a wired analog net, used a standard processing environment that was specifically programmed and configured for the items of the study. The system, as developed, gives the opportunity to monitor the different parameters of the phenomena, but presents some drawbacks, as those typical of these configuration. The second system has been designed on a “pure” digital basis. A specific sensor has been designed around an integrated triaxial microchip accelerometers, with different capabilities in terms of local processing, data storage and data transfer. In particular the actual version uses a can bus for data exchange between the sensor’s net and the acquisition unit. Wireless connection is anyway implemented and available under requests. The central unit, built around an ARM 7 μcontroller, govern the data interchange, the relative storage and communication with the collecting data center. During the first part of the work, a PC was used as a large mass storage unit, but remote control and storage has been implemented and tested, to be used during the second part of the work. Inside the paper, the description of the systems and the most interesting results will be presented and discussed