Field evaluation of ZigBee-based wireless sensor networks for automated resource tracking on construction sites

Automation systems for positioning and tracking construction resources, such as equipment, materials, tools and labourers involved on site, provide engineers with reliable operations data, enhanced situational awareness and more effective project control. Technological advances have opened up the prospect of applying state-of-the-art radio frequency (RF) technologies for automatic data acquisition in construction engineering. This paper proposes a cost-effective, ZigBee-based wireless sensor networks (WSN) solution for automated resource tracking on construction sites. A prototype of the ZigBee WSN was developed in house, consisting of a group of stationary and mobile nodes that can communicate with one another. For concept proving and performance evaluation, field trials of the ZigBee WSN system were carried out on two construction sites in Hong Kong, including a high-rise building and an open-trench for laying down 315 mm-diameter polyethylene (PE) pipeline. In the field experiments, multiple stationary nodes were fixed at pre-defined locations on site. Real time ranges of a mobile node in relation to each stationary node were estimated by applying the localization methodology of received signal strength indicator (RSSI). Practical performances of the ZigBee-based WSN under realistic construction environments are discussed, and recommendations made for future research.