Analysis of the detachment of citrus fruits by vibration using artificial vision

The vibratory behaviour of citrus fruits is studied using slow-motion cameras in order to gain a better understanding of the parameters involved in fruit detachment when mechanical harvesting is done using shakers. Single citrus fruits with a small portion of stem were vibrated using strokes from 60 mm to 180 mm and frequencies from 3 Hz to 18 Hz. The movement was recorded at 300 fps and the main parameters considered for fruit detachment were determined through the analysis of the video sequences. Image-processing algorithms created for this purpose were applied to the automated estimation of the centroid of the fruit, the angle of the stem pistil axis, and the position of some selected points in the fruit in each frame of the video sequences to obtain dynamic parameters such as the position, speed and acceleration of the fruit during the movement until it is detached. The signals obtained from the image processing were filtered, providing results in accordance with the calibration systems. In general, results suggest that the inertial forces transmitted to the fruit were lower than the tensile forces required to detach the fruit by pulling it in the stem pistil direction. The largest peaks were observed using long strokes that required fewer cycles for detachment. On the other hand, short strokes combined with high frequencies needed more cycles, and thus a fatigue phenomenon was present. Short strokes and low frequencies were unable to detach some fruit. (C) 2014 IAgrE. Published by Elsevier Ltd. All rights reserved.This work was founded by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA) through the projects RTA2009-00118-C02-01 and RTA2009-00118-C02-02, and co-founded by European FEDER founds.Torregrosa Mira, A.; Albert Gil, FE.; Aleixos Borrás, MN.; Ortiz Sánchez, MC.; Blasco Ivars, J. (2014). Analysis of the detachment of citrus fruits by vibration using artificial vision. Biosystems Engineering. 119:1-12. https://doi.org/10.1016/j.biosystemseng.2013.12.010S11211

Non-destructive technologies for fruit and vegetable size determination - a review

Here, we review different methods for non-destructive horticultural produce size determination, focusing on electronic technologies capable of measuring fruit volume. The usefulness of produce size estimation is justified and a comprehensive classification system of the existing electronic techniques to determine dimensional size is proposed. The different systems identified are compared in terms of their versatility, precision and throughput. There is general agreement in considering that online measurement of axes, perimeter and projected area has now been achieved. Nevertheless, rapid and accurate volume determination of irregular-shaped produce, as needed for density sorting, has only become available in the past few years. An important application of density measurement is soluble solids content (SSC) sorting. If the range of SSC in the batch is narrow and a large number of classes are desired, accurate volume determination becomes important. A good alternative for fruit three-dimensional surface reconstruction, from which volume and surface area can be computed, is the combination of height profiles from a range sensor with a two-dimensional object image boundary from a solid-state camera (brightness image) or from the range sensor itself (intensity image). However, one of the most promising technologies in this field is 3-D multispectral scanning, which combines multispectral data with 3-D surface reconstructio

Grader: A review of different methods of grading for fruits and vegetables

Grading of agricultural produce especially the fruits and vegetables has become a perquisite of trading across borders.  In India mostly fruit growers grade the fruit manually.  Manual grading was carried out by trained operators who considered a number of grading factors and fruit were separated according to their physical quality.  Manually grading was costly and grading operation was affected due to shortage of labor in peak seasons.  Human operations may be inconsistent, less efficient and time consuming.  New trends in marketing as specified by World Trade Organization (WTO) demand high quality graded products.  Farmers are looking forward to having an appropriate agricultural produce-grading machine in order to alleviate the labor shortage, save time and improve graded product’s quality.  Grading of fruits is a very important operation as it fetches high price to the grower and improves packaging, handling and brings an overall improvement in marketing system.  The fruits are generally graded on basis of size and graded fruits are more welcome in export market.  Grading could reduce handling losses during transportation. Grading based on size consists of divergent roller type principle having inclination, expanding pitch type, inclined vibrating plate and counter rotating roller having inclination type graders.  Weight grading based on density and specific gravity of agricultural commodities.  The need to be responsive to market demand places a greater emphasis on quality assessment, resulting in the greater need for improved and more accurate grading and sorting practices.  Size variation in vegetables like potatoes, onions provided a base for grading them in different categories.  Every vegetable producing country had made their own standards of different grades keeping in view the market requirements.   Keywords: grading, handling, packaging, color sensor, specific gravity, Indi

BlockDrop: Dynamic Inference Paths in Residual Networks

Very deep convolutional neural networks offer excellent recognition results, yet their computational expense limits their impact for many real-world applications. We introduce BlockDrop, an approach that learns to dynamically choose which layers of a deep network to execute during inference so as to best reduce total computation without degrading prediction accuracy. Exploiting the robustness of Residual Networks (ResNets) to layer dropping, our framework selects on-the-fly which residual blocks to evaluate for a given novel image. In particular, given a pretrained ResNet, we train a policy network in an associative reinforcement learning setting for the dual reward of utilizing a minimal number of blocks while preserving recognition accuracy. We conduct extensive experiments on CIFAR and ImageNet. The results provide strong quantitative and qualitative evidence that these learned policies not only accelerate inference but also encode meaningful visual information. Built upon a ResNet-101 model, our method achieves a speedup of 20\% on average, going as high as 36\% for some images, while maintaining the same 76.4\% top-1 accuracy on ImageNet.Comment: CVPR 201

Sensors for product characterization and quality of specialty crops—A review

This review covers developments in non-invasive techniques for quality analysis and inspection of specialty crops, mainly fresh fruits and vegetables, over the past decade up to the year 2010. Presented and discussed in this review are advanced sensing technologies including computer vision, spectroscopy, X-rays, magnetic resonance, mechanical contact, chemical sensing, wireless sensor networks and radiofrequency identification sensors. The current status of different sensing systems is described in the context of commercial application. The review also discusses future research needs and potentials of these sensing technologies. Emphases are placed on those technologies that have been proven effective or have shown great potential for agro-food applications. Despite significant progress in the development of non-invasive techniques for quality assessment of fruits and vegetables, the pace for adoption of these technologies by the specialty crop industry has been slow

Artificial intelligence machine vision grading system

Thesis (M. Tech.) -- Central University of Technology, Free State, 201

Redesigning Public Speaking: A Case Study in the Use of Instructional Design to Create the Interchange Model

This case study describes the redesign of Public Speaking at a Research I institution. An instructional analysis revealed strengths of and concerns about the existing model--large lecture with small lab sections. Criteria for a new model emerged from that analysis, all of which hinged on an overarching goal: The course should incorporate learning theory and disciplinary theory and should result in student learning, student skill development, and enhanced satisfaction among stakeholders. The Interchange Model, which included some online delivery, was developed to meet identified needs and was fleshed out with course materials and semester plans. The model was piloted and then fully implemented with positive results

Comparison of a Lightweight Experimental Shaker and an Orchard Tractor Mounted Trunk Shaker for Fresh Market Citrus Harvesting

[EN] A designed lightweight experimental shaker successfully used to collect ornamental oranges has been tested to harvest fresh market citrus. The aim of this study was to evaluate the removal efficiency and operational times of this experimental device compared to an orchard trunk shaker. Three different collecting systems were studied. 'Caracara' citrus trees were tested. Removal efficiency, vibration parameters, fruit and tree damages, and fruit quality were measured. A high-speed camera was used to record operational times and determine cumulative removal percentage over vibration time. The canvases on the ground reduced the severe fruit damages but were not useful to protect against light damages. The experimental shaker produced a higher percentage of slightly damaged oranges. No significant differences in removal efficiency were found between the two harvesting systems. However, removal efficiency using the experimental device could be reduced by 40 percent and working time increase by more than 50 percent when access to the main branches was difficult. In agreement with previous results, the curve representing the branch cumulative removal percentage in time followed a sigmoidal pattern. A model was built showing that during the first 5 s more than 50 percent of the fruits were detachedThis research has been fund by the European Agricultural Fund for Rural Development and cofounded by the Ministerio de Agricultura, Pesca y Alimentacion (project GO "Avances tecnologicos para la modernizacion y la sostenibilidad en la produccion de citricos CITRUSTECH").Ortiz Sánchez, MC.; Torregrosa, A.; Castro-García, S. (2021). Comparison of a Lightweight Experimental Shaker and an Orchard Tractor Mounted Trunk Shaker for Fresh Market Citrus Harvesting. Agriculture. 11(11):1-10. https://doi.org/10.3390/agriculture11111092110111