Wireless sensor module for 3-axis vibration and tilt monitoring on the structural building

In this paper, a simple and low-cost wireless sensor module has been developed for structural health monitoring (SHM) purposes. The module can be divided into three main parts: sensing unit, data acquisition (DAQ) unit, and data communication (DC) unit. The sensing unit is three-axis vibration and tilt sensor. It is composed using single MEMS accelerometer e.g. MMA7361L, and signal conditioning circuit for both tilt and vibration parameters. The DAQ unit function for A/D converter and data formatting, built based on a microcontroller PIC16F873. Whereas DC unit is radio (RF) transceiver, it is used to communicate with the control module (monitoring room) wirelessly. In here, we use RF-transceiver YS-C20K. In the control room, vibrations and tilts data are analysed using the developed software to get information about dynamics condition of structural building being monitored. Results of experiment and evaluation show the tilt sensor is capable to detect up to ± 30 degrees dynamic range with resolution of about 0.05 degrees, while the vibration sensor can achieved up to sensitivity of (80 V/g) with noise compensation. To get portability and easiness in field installation, the sensor system was packaged into one module.