Remote sensing device for structural health monitoring systems

In this paper a system based on piezoelectric sensors and on transmitter/receiver antennas, capable to monitor the vibration state of a structure and to communicate such information in remote transmission, is presented. The device is studied with the aim to build a system to monitor the integrity of a structure at distance. This is desirable in such cases where it is not possible or convenient to have a continuous direct access to the structure, as i.e. for a transportation system or a space platform. The information of the integrity of the structure can be monitored, in such way, from a remote ground station. The bi-directional transmission allows extending the capabilities of the piezoelectric sensors as exciters in order to sense but also to produce ultrasonic waves, widely employed in the field of the non-destructive testing to detect structural damages. The on board system of the device is composed of a PZT piezo patch as sensor, of a filtering circuit to avoid the aliasing phenomena and to isolate the required frequencies, of a microcontroller and a transmission system. The operations of data digitalisation and processing are performed by a microcontroller, model Freescale HCS-12DP512, where the A/D converter is provided of a memory for data storage and software management. The communication system is composed of a modem, model Tigertronics BP-2, and of a transmitter Yaesu Y-3E. © (2010) by the International Conference on Adaptive Structures and Technologies (ICAST).