Sistema de monitoramento em tempo real dos níveis acústicos urbanos baseado em redes de sensores sem fio

Abstract

This course conclusion work consists of the development of a real-time monitoring system of sound levels in urban environments, helping primarily in the detection of sound pollution sources. The project is composed of a wireless network of smart objects, capable of communicating between each other through open communication protocols; a data server which stores the data coming from the wireless sensor network; and a webpage, that shows the information in sound map format. The wireless network has its link layer based on IEEE 802.15.4 and uses IPv6 protocol in the network layer, along with the adaptation layer for constrained devices 6LoWPAN and RPL protocol for the network topology and packet routing. The network is composed of sensor nodes spread across different points, which have its position determined by GPS. Through a microphone and a preamplifier circuit, these nodes measure the sound intensity of the environment in which they’re in. Each of these sensor nodes sends the data obtained in UDP packets through the network, until they arrive at the network coordinator. The network coordinator is responsible of sending the data to a data server in the Internet via cellular network. On this server, all data is stored in a database, which is continuously consulted by a script of the webpage, that shows visually the current information in sound map format. The results obtained until the end of this work showed that the solution used on this system is functional, however, it uses most part of the RAM of the microcontrollers. The data traffics in the wireless sensor network effectively through the Internet protocols.