Cyber-physical system-based real-time monitoring and visualization of greenhouse gas emissions of prefabricated construction

The excessive emissions of greenhouse gases (GHGs) from the construction industry are currently receiving global attention. Many breakthroughs have been made in assessing GHG emissions, including pre- and post-evaluation methods. However, the real-time monitoring of GHG emissions has not been studied on a large scale. The real-time GHG emissions of construction sites must be monitored, and the use of clean energy and technologies must be facilitated by comparing real-time GHG emissions under different mechanical and energy use conditions. Thus, this study proposes a cyber-physical system (CPS)based real-time monitoring and visualization of the GHG emissions of prefabricated construction, which is widely practiced in the construction industry. In this system, acceleration sensors monitor the operational status of tower cranes, barometric sensors monitor the running state of construction elevators, and a Global Positioning System module records the travel time of on-site transfer vehicles to detect and transmit the running time of construction machineries to a remote server via a preinstalled Wi-Fi or General Packet Radio Service module. Furthermore, the database can store the model number, quantity, and power of each element of construction machinery and GHG emission factors. Thus, GHG emissions from prefabrication sites can be calculated in real time using the specified quantitative model in the remote server. In addition, GHG emission data can be displayed using a visual model and 2D charts on fixed and mobile devices. The development process of each part of the CPS-based system is also described in this paper. (C) 2019 Elsevier Ltd. All rights reserved.