Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/30276
Title: Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing
Other Titles: Determinação das propriedades modais do sistema fruto-pedúnculo do café por vídeos de alta velocidade e processamento de imagens digitais
Keywords: Image segmentation
Mechanical harvesting
Mechanical vibrations
Coffee - Harvesting
Segmentação de imagens
Colheita mecânica
Vibrações mecânicas
Café - Colheita
Issue Date: Jan-2016
Publisher: Universidade Estadual de Maringá
Citation: VILLIBOR, G. P. et al. Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing. Acta Scientiarum. Technology, Maringá, v. 38, n. 1, p. 41-48, Jan./Mar. 2016.
Abstract: Detachment of coffee fruit is usually accomplished by means of mechanical impacts and vibrations applied to the plant. Modal properties of the coffee fruit-stem system represent important information for efficient and selective harvesting. This study aimed to determine the modal parameters of the coffee fruit-stem system, such as natural frequency and damping coefficient, using high speed digital videos. With image processing techniques, it was obtained the resulting displacement of the system subjected to an impulse. The modal parameters were determined by the logarithmic decrement method, considering the system as underdamped. The use of high-speed video and digital image processing techniques allowed the simple and reliable determination of modal parameters of the coffee fruit-stem system. Natural frequencies for the coffee fruit-stem system were 11.62 and 13.29 Hz; the damping coefficient was 0.0253 and 0.029 N s m-1, and the equivalent stiffness was 8.61 and 7.09 N m-1 for red and green ripening stages, respectively. It was found overlap of resonance bands, between the ripening stages red and green, hindering the selective mechanical detachment in the first natural frequency range of the coffee fruit-stem system.
URI: http://repositorio.ufla.br/jspui/handle/1/30276
Appears in Collections:DEG - Artigos publicados em periódicos



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