Estratégia de navegação com multi-robôs em ambientes confinados visando melhoria da cobertura de sinal de rádio

Abstract

Efficient communication between mobile robots is a critical factor for performing inspection tasks in confined environments, such as underground galleries, ducts, and mines. In this context, radio signal propagation faces significant challenges due to the presence of obstacles, signal attenuation, and multipath effects. This dissertation proposes a navigation strategy for multiple robots that improves radio signal coverage, ensuring stable and continuous communication during teleoperation and inspection operations. The approach is based on the dynamic positioning of relay robots, considering the environment’s geometry and signal propagation models. Different signal propagation models were analyzed, including the TwoRay, LogNormal, and LogNormal Shadowing models, allowing for the estimation of signal power loss under various conditions. For each propagation model, a statistical analysis was conducted that divides the inspected environment into different regions of interest and determines the best model for each region, isolating local propagation characteristics. The main contribution of this dissertation is the development of a multi-robot navigation algorithm that optimizes communication in confined environments, enabling the expanded use of mobile robots in critical tasks. For the implementation of the approach, signal power data were collected from the Ubiquiti M900 radio interface. In addition, two robots were controlled: the EspeleoRobô, which functions as the network client, and the Pioneer 3-DX, which operates as a signal repeater. To validate the proposed strategy, experiments were carried out in controlled scenarios and simulations in the CoppeliaSim environment. The results show that the implementation of relay robots improves signal coverage by more than 50% and significantly reduces communication loss points, enabling safer and more efficient operations.