Design of low cost wireless sensor network for Health Monitoring of larger structures

To monitor the structural health of civil and mega mechanical structures, a wired sensor system is been used traditionally. From an economical and a maintenance point of view, the traditional wired SHM systems have limitations when used in offshore wind turbine, wave energy devices and other civil structures. Wireless sensor is getting importance because of its low price and suitability for mentioned applications. Commercially the available wireless sensor systems for SHM are expensive; hence there is a need of cheap wireless sensor network. A low cost wireless sensor network (WSN) for a Health Monitoring of these structures is proposed in this work. This work is divided into two tasks one, design of wireless sensor units (WSU). To measure the response of the system a WSU is designed by using available standard electronic components. This WSU consists of one acceleration senor, micro-controller, a radio frequency (RF) transceiver, and a battery power supply. The second part of the work consists of acceleration measurements for a four starry shear frame which is excited by shaker. Then the Autoregressive (AR) model coefficients are determined remotely for measured data at each starry of the shear frame. These coefficients are transferred to the master WSU which is connected to the computer using USB port for comparison with stored data base to recognize the pattern. In the extension to this work a Damage Index calculations could be performed at remote WSU.