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Abstract(s)
Esta dissertação apresenta uma técnica de localização baseada em Ultrassons para espaços
confinados que recorre à transmissão de sinais OFDM periódicos. O uso de sinais OFDM
permite tirar partido da periodicidade do sinal emitido para operar de forma contínua e
autónoma. Adicionalmente através da utilização de um algoritmo de localização assíncrono
baseado na diferença de tempos de chegada é possível estimar a localização com uma resolução
na ordem dos centímetros. Para gerar os sinais, emitir, gravar e posterior tratamento do sinal
gravado e localização foram utilizados quatro emissores acústicos, um microfone e uma placa
de som conectada a um computador pessoal com o software Matlab. O sistema opera numa
banda de frequências de 10 a 30 kHz, com uma precisão de alguns centímetros. No fim do
trabalho foi obtido um sistema totalmente funcional, pronto a ser implementado num veículo
autónomo ou em qualquer outro dispositivo que careça de localização.
ABSTRACT: This dissertation presents an ultrasound-based localization technique for confined spaces that uses periodic OFDM signal transmission. The use of OFDM signals makes it possible to take advantage of the periodicity of the emitted signal to operate continuously and autonomously. In addition, from the use of an asynchronous location algorithm based on the difference in arrival times is possible to estimate the localization with a accuracy in order of a few centimeters. To generate signals, emit, record and further processing of the recorded signal and localization was used, four speakers, a microphone and a sound card connected to a computer with Matlab software. The system operates in a frequency band from 10 to 30 kHz, with an accuracy of a few centimeters. At the end of the work, a fully functional system was made, ready to be implemented in an autonomous vehicle that needs location.
ABSTRACT: This dissertation presents an ultrasound-based localization technique for confined spaces that uses periodic OFDM signal transmission. The use of OFDM signals makes it possible to take advantage of the periodicity of the emitted signal to operate continuously and autonomously. In addition, from the use of an asynchronous location algorithm based on the difference in arrival times is possible to estimate the localization with a accuracy in order of a few centimeters. To generate signals, emit, record and further processing of the recorded signal and localization was used, four speakers, a microphone and a sound card connected to a computer with Matlab software. The system operates in a frequency band from 10 to 30 kHz, with an accuracy of a few centimeters. At the end of the work, a fully functional system was made, ready to be implemented in an autonomous vehicle that needs location.
Description
Keywords
AGV Matlab OFDM Método de Newman Papoulis-Gerchberg TDOA