Development and Validation of an Autonomous System for Measurement of Sunshine Duration.

Autor: Rocha ÁBD; Academic Unit of Mechanical Engineering, Federal University of Campina Grande, Campina Grande, Paraíba 58429-900, Brazil., Fernandes EM; Academic Unit of Mechanical Engineering, Federal University of Campina Grande, Campina Grande, Paraíba 58429-900, Brazil., Santos CACD; Academic Unit of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58429-900, Brazil., Diniz JMT; School of Apprentices-Sailors of Pernambuco, Navy of Brazil, Recife, Pernambuco 53110-901, Brazil., Junior WFA; Academic Unit of Mechanical Engineering, Federal University of Campina Grande, Campina Grande, Paraíba 58429-900, Brazil.
Jazyk: angličtina
Zdroj: Sensors (Basel, Switzerland) [Sensors (Basel)] 2020 Aug 16; Vol. 20 (16). Date of Electronic Publication: 2020 Aug 16.
DOI: 10.3390/s20164606
Abstrakt: This paper presented an autonomous electronic system for sunshine duration (SD) monitoring based on the contrast method and developed to operate on a horizontal surface. The prototype uses four photoresistors arranged at 90° in a 20 mm diameter circumference separated by a shading structure used to create a shadow pattern on the detection element. Photoresistors are inserted in individual signal conditioning circuits based on the association between Wheatstone bridges and operational amplifiers to provide an analog signal to the microcontroller unit. The determination of SD occurs through the implementation of fuzzy logic with numerical calculation methods to estimate the probability (f) of solar disk obstruction and estimate SD values. The system does not require additional adjustments after installation or use of energy sources for operation due to the use of an internal battery with charge recovery by solar panels. Experimental results of the proposed system were validated with the ones provided by a government meteorology station. Statistical analysis of the results showed a confidence index (c) greater than 90%, with a precision of 94.26%. The proposed system is a feasible low-cost solution to the available commercial systems for the measurement of sunshine duration.
Databáze: MEDLINE
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