Banca de DEFESA: BRUNO AUGUSTO FERREIRA VITORINO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : BRUNO AUGUSTO FERREIRA VITORINO
DATA : 06/09/2018
HORA: 09:00
LOCAL: Auditório do nPITI
TÍTULO:

Sigma-Delta Thermal Converter with automatic adjustment of operating range for incident radiation measurement

PALAVRAS-CHAVES:

thermoresistive sensors, sigma-delta modulation, thermal sigma-delta, pyranometers, bolometers, thermistors

PÁGINAS: 80
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Medidas Elétricas, Magnéticas e Eletrônicas; Instrumentação
RESUMO:

The incident thermal radiation measurement, including infrared and solar radiation, has several applications and increasing demand. In the infrared (IR) radiation measurement, resistive microbolometers are the most used sensors, being applied in complex thermal imaging and detection systems. Some researches aims to increase the sensitivity of IR detection systems, as well as to integrate new functions such as analog-to-digital conversion, together with sensors. The measurement of solar radiation has as main applications the meteorology, photovoltaic plants and studies for agriculture, being the pyranometer the most used instrument. Thermoresistive sensors have been used to measure temperature, fluid speed and direction and radiation. In several architectures the sensor operates in closed loop, increasing the sensitivity, decreasing the response time and linearizing the systems response. The most used closed-loop architectures are the Wheatstone feedback bridge, control systems, capacitive coupling feedback and Thermal Sigma-Delta Modulator (TΣ∆M). TΣ∆M is a closed-loop measurement approach where the sensing element performs part of the Σ∆ modulation in the thermal domain. A new architecture is proposed in this work for measuring thermal incident radiation using thermoresistive sensors, were the modulator input range is automatically adjusted to fit the complete thermal radiation. The proposed architecture is compared with a similar one, which uses the same transducer interface circuit but without range adjustment, and is validated experimentally with a reference pyranometer. The proposed architecture has the main advantage of presenting a signal-to-noise ratio, and sensitivity, that is independent of the ambient temperature range definition. Experimental results for ambient temperature range of 45 ◦C shows a gain of 13 dB over the similar one.

MEMBROS DA BANCA:
Presidente - 1284113 - SEBASTIAN YURI CAVALCANTI CATUNDA
Interno - 2140683 - DIOMADSON RODRIGUES BELFORT
Externo ao Programa - 1837410 - VALENTIN OBAC RODA
Externo à Instituição - JOSE CAMARGO DA COSTA
Externo à Instituição - RAIMUNDO CARLOS SILVÉRIO FREIRE - UFCG