Simulation Study of Citrus Tree Canopy Motion During Harvesting Using a Canopy Shaker

Savary, S. K. J. U.; Ehsani, Reza; Schueller, John K.; Rajaraman, B. P.

doi:10.13031/2013.34892

Cited by 32 publications

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“…Similar studies on canopy shakers report the high damping values of the fruitbearing branches that limit the fruit removal efficiency (Savary et al, 2010). Adapting the trees is the key to mechanical harvesting using canopy shaking systems, principally in the interior and lower areas of the canopy, which are less accessible to the rods (Ravetti & Robb, 2010).…”

Section: Harvestermentioning

confidence: 95%

“…This difficulty could be overcome by including a system that would allow the vibrating mechanism to operate in closer proximity to the tree and thus ensure the permanent contact of the rods with the fruit-bearing branches during movement of the vibration system. Furthermore, the shape of the tree must be trained to allow mechanical harvesting by canopy shaking systems in order to achieve high fruit removal efficiency levels (Savary et al, 2010).…”

Section: Harvestermentioning

confidence: 99%

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Vibration parameters assessment to develop a continuous lateral canopy shaker for mechanical harvesting of traditional olive trees

Sola-Guirado¹,

Jiménez-Jiménez²,

Blanco-Roldán³

et al. 2016

Span. j. agric. res.

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certain operations, particularly fruit harvesting. Nevertheless, traditional plantations are widespread globally and play an important social and environmental role, which makes it difficult or unfeasible to substantially change these plantations or even eliminate them entirely. Particularly notable in this respect is olive cultivation in the Mediterranean basin, where 97% of world production is concentrated. More specifically, in Spain, which is home to more than 50% of world olive oil production (AICA, 2014), there are 2,420,000 ha of olive crop, and traditional plantations RESEARCH ARTICLE OPEN ACCESS AbstractThe fruit harvesting is a key factor involving both product quality and profitability. Particularly, mechanical harvesting of traditional oil olive orchards is hint by tree training system for manual harvesting, tree size and several and slanted trunks which makes difficult trunk shaker work. Therefore, canopy shaker technology could be a feasible alternative to develop an integral harvester able to work on irregular canopies. The aim of this research was to determine vibration parameters applied to the olive tree for efficient mechanical harvesting by canopy shaker measuring fruit removal efficiency and debris. In this work, a continuous lateral canopy shaker harvester has been developed and tested on large olive trees in order to analyse the operating harvester parameters and tree properties to improve mutual adaptation. Vibration amplitude and frequency, rod density and ground speed were assessed. Vibration amplitude and frequency beside ground speed were decisive factors on fruit removal efficiency. Increasing rod density has not influenced on removal efficiency although it increased significantly debris. Promising results has been reached with 77.3% of removal efficiency, applying a 28 s shaking duration, 0.17 m amplitude vibration and 12 rod drum. This result was obtained reporting 0.26 s of accumulative shaking time over 200 m/s 2 resultant acceleration. The canopy shaker mechanism enabled more than 65% of detached fruits to fall vertically, facilitating catch fruit. In order to improve removal efficiency it is advisable to adapt trees, set high amplitude in the shaker mechanism, and enhance the contact time between rods and tree.Additional key words: Olea europaea L.; fruit detachment; integral harvester; frequency; amplitude; removal efficiency.

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Section: Harvestermentioning

confidence: 95%

Section: Harvestermentioning

confidence: 99%

Vibration parameters assessment to develop a continuous lateral canopy shaker for mechanical harvesting of traditional olive trees

Sola-Guirado¹,

Jiménez-Jiménez²,

Blanco-Roldán³

et al. 2016

Span. j. agric. res.

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“…An isotropic elastic material model is considered for both the tree limb and the tine. The mechanical and physical properties of citrus wood were set based on results obtained from laboratory experiments on green citrus wood samples (Gupta , 2015;Savary et al, 2010). The interaction between the tree limb and the tine, which results in their dynamic motions when they come into contact, was defined using Abaqus tube-to-tube elements (ITT3), as shown in figure 5.…”

Section: Finite Element Modelmentioning

confidence: 99%

“…Computer simulation has been used in the past by Phillips et al (1970), Fridley and Yung (1975), and Savary et al (2010) to design mechanical harvesters. However, the current study presents an economical way to design a harvester using statistical models of limb prototypes, finite element methods, and response surface based design optimization.…”

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confidence: 99%

Optimization of a Citrus Canopy Shaker Harvesting System: Mechanistic Tree Damage and Fruit Detachment Models

2016

Trans. ASABE

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Mechanization of fruit and nut harvesting is becoming increasingly important because of a significant rise in the cost of manual harvesting. This work proposes a progressive analytical approach for the design and optimization of a citrus canopy shaker harvesting machine. The approach was formulated using finite element (FE) methods to find the optimum design parameters of the machine. The design parameters were defined in terms of a configuration (or stiffness) of shaking rods and two operating parameters: shaking frequency and shaking amplitude. The formulated methodology consists of determining the properties of wood, statistical modeling of the tree limbs, developing mechanistic models, and performing optimization using FE simulations. The proposed methodology employs the response surface methodology or surrogate models to quantify the objective functions, and Pareto-optimal search techniques to find the optimum designs. Three sets of machine parameters were proposed in this study to minimize tree damage and maximize fruit removal. These optimal parameters were proposed based on the configuration and distribution of limbs and fruits in a medium-size citrus tree. The optimized tine configuration of the middle and bottom section of the canopy shaker consists of a solid rod made of polyamide reinforced with 50% long glass fibers and a hollow tube made of hardened steel in a 3:1 ratio by length. These tines, when vibrating at a high frequency of 7.8 Hz and low amplitude of 3.81 to 5.08 cm (1.5 to 2 in.) and a low frequency of 3 to 3.5 Hz and high amplitude of 13.9 to 15.2 cm (5.5 to 6 in.), provide a 25% to 30% reduction in damage to the tree limbs in the bottom and middle zones of the tree. Similarly, changes to the top sections of the canopy shaker with another set of optimized tine configurations resulted in a 40% to 45% reduction in the damage to the limbs of the top section of the tree canopy. The optimized tine configuration, thus proposed for the top section of the canopy shaker, is made of a solid rod of polyamide reinforced with 60% long glass fibers and vibrates at a frequency of 6.5 to 7.5 Hz with an amplitude of 7.6 to 8.9 cm (3 to 3.5 in.

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“…Computer simulation provides an efficient tool for determining the response of the whole tree to practically any vibratory force by dividing the tree into a large number of small element sections, with the mass and stiffness properties of each section known from measurements (Phillips et al 1970;Yung and Fridley, 1975;Savary et al, 2010Savary et al, , 2011. However, it is unlikely that a harvester designed based on the response of a few trees will perform satisfactorily for all other trees.…”

mentioning

confidence: 99%

Optimization of a Citrus Canopy Shaker Harvesting System: Properties and Modeling of Tree Limbs

Gupta¹,

Ehsani²,

Kim³

2015

Trans. ASABE

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This article presents a part of the research work for the design and optimization of a fruit tree harvesting system using numerical methods. The analytical framework for the optimization is formulated based on a continuous canopy shaker that harvests citrus crops, primarily Valencia oranges (Citrus sinensis). Tree limbs are modeled analytically in the numerical based design optimization of a shaker that requires information regarding the limb configuration and properties. The objective of this study is to formulate a mathematical model to predict the configuration of primary limbs and to determine the properties of citrus wood. The tree limbs, thus proposed, are statistical prototypes or representations that account for the 5th, 25th, 50th, 75th, and 95th percentiles of actual tree limbs from random individual citrus trees. Polynomial response surface models were developed to predict sectional properties of the statistical model of the tree limbs. The distributions of the secondary branches and fruits were also predicted to model their effect on the dynamic response of the tree limbs. A three-point bending test, specific gravity test, moisture content test, and damping test were conducted on freshly cut samples of citrus wood. An elastic modulus of 8.5 GPa and modulus of rupture of 67.3 MPa were calculated from a load-deflection curve, and a density of 1450.8 kg m-3 , moisture content of 42%, and damping ratio of 10.78 were measured. Although the proposed methodology was developed for a canopy shaker, it could be easily implemented for other vibratory harvesters, such as limb shakers, foliage shakers, and over-the-row harvesters.

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Simulation Study of Citrus Tree Canopy Motion During Harvesting Using a Canopy Shaker

Cited by 32 publications

References 0 publications

Vibration parameters assessment to develop a continuous lateral canopy shaker for mechanical harvesting of traditional olive trees

Vibration parameters assessment to develop a continuous lateral canopy shaker for mechanical harvesting of traditional olive trees

Optimization of a Citrus Canopy Shaker Harvesting System: Mechanistic Tree Damage and Fruit Detachment Models

Optimization of a Citrus Canopy Shaker Harvesting System: Properties and Modeling of Tree Limbs

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