Exploring Robot Communication Methods for Geological Activities

Many geological activities are developed below the surface, such as underground mining and cave exploring. These environments often present characteristics that are harmful to people, like poisonous gases and animals, and the risk of roof collapse or explosions. In this sense, the academy and the industry are developing teleoperated, and even autonomous, robots that can perform the inspection and mapping activities and prevent injuries for people working at those places. One of the most significant challenges faced in this type of development is communication between the robot and the base station or other robots. There is a high flux of information that needs to be transmitted, such as the robot's telemetry, remote commands, a video input, sensor data, among others. Depending on the environment, the use of cables is not viable, and the range of conventional wireless equipment does not transcend a few meters. When the signal goes weaker, all the information tends to interfere with each other, what may result in packets collision and the inability to send the remote commands to the robot. In this study, we evaluated several wireless technologies to improve the robot communication on unstructured and underground environments. We used different communication systems and we applied a distinct approach to increase the robustness to package loss. We also studied how to prioritize the crucial information for the robot operation, such as remote commands and telemetry. This study will focus on LoRa, a long-range network technology for Internet of Things (IoT); the Ubiquiti M900, a radio commonly used in multi-point networks; Decawave, an UWB localization system for indoor environments; and the Reseiwe WL24, a radio module for industrial Wi-Fi. The main goal of this work is to investigate the advantages and downsides of each communication technology and to develop a combination of them that allows the best communication possible under most scenarios.