Temperature prediction model in the main ventilation system of an underground mine

A model to forecast the underground temperature in a mine ventilation circuit was developed on the basis of a case study and actual data describing temperature, airflow, and drift length collected over several years. A mathematical model featuring seven variables with interactions provided reliable predicted temperatures, achieving a correlation of R2 = 0.933 with an estimation error of ±2 °C. Its soundness was proven using both the node-to-node analysis and the multi-node approach. The multi-node approach was shown to be an interesting option to model underground mining environments. This model can be very useful to predict the temperature evolution along the main ventilation system, determine the best workplace conditions in terms of temperature, and analyze different planning scenarios of the mine. Moreover, some recommendations are presented for obtaining reliable data when using temperature sensors and the model in a U-shaped ventilation system.Peer ReviewedPostprint (published version

Fully flexible textile antenna-backed sensor node for body-worn UWB localization

A mechanically flexible textile antenna-backed sensor node is designed and manufactured, providing accurate personal localization functionality by application of Decawave's DW1000 Impulse Radio Ultra-Wideband (IR-UWB) Integrated Circuit (IC). All components are mounted on a flexible polyimide foil, which is integrated on the backplane of a wearable cavity-backed slot antenna designed for IR-UWB localization in Channels 2 and 3 of the IEEE 802.15.4-2011 standard (3744 MHz-4742.4 MHz). The textile antenna's radiation pattern is optimized to mitigate body effects and to minimize absorption by body tissues. Furthermore, its time-domain characteristics are measured to be adequate for localization. By combining the antenna and the bendable Printed Circuit Board (PCB), a mechanically supple sensor system is realized, for which the performance is validated by examining it as a node used in a complete localization system. This shows that six nodes around the body must be deployed to provide system coverage in all directions around the wearer. Even without using sleep mode functionalities, the measurements indicate that the system's autonomy is 13.3 h on a 5 V 200 mAh battery. Hence, this system acts as a proof of concept for the joining of localization electronics and other sensors with a full-textile antenna into a mechanically flexible sensor system

Performance analysis of IEEE 802.15.6 for underground disaster cases

CICIOGLU, MURTAZA/0000-0002-5657-7402WOS: 000479023200008Nowadays, there are many underground working areas, such as mines and tunnels, which are considered with the scope of the hazardous working area. The use of wireless sensor network (WSN) technologies to ensure the safety of the workers as well as the efficient use of the resources in these areas provides great benefits. Our study aims to design a safe system with the help of WSN technologies developed for disaster cases. The proposed architecture using the IEEE 802.15.6 standard on each worker consists of several wireless sensor nodes for sensing temperature, air-flow, humidity, dust, gas concentration, and etc., and a coordinator that manages all these nodes. The performance of the proposed architecture is evaluated using the Riverbed Modeler simulation program in terms of throughput, end-to-end delay, and energy consumption metrics. The analysis shows that the IEEE 802.15.6 standard creates a reliable monitoring and communication network with reasonable service quality in underground areas and tunnels