A review of unilateral grippers for meat industry automation

With the expectation that meat consumption will grow by 12% over the next decade, coupled with the reported labour issues and viruses attacking human and animal health, there is a growing requirement for red meat slaughterhouse automation. Changes to current abattoir setups and processes are necessary to realise for sustainable, low-cost and scalable automation. However, to achieve such autonomous nirvana, simple, cost-efficient and robust tooling to support these systems are sought. This includes grippers used to hold, manipulate and transport workpieces, such as primal cuts of red meat, for example, with the simplest type being unilateral gripping systems. Scope and approach This paper critically reviews various unilateral gripping solutions available in cross-industry sectors or developed in research that could be used or adapted for the meat industry. Criteria for such tooling are simplicity, low-cost, durability and robustness, whilst being capable of gripping highly deformable objects of various structures and maintaining safety and hygiene standards. The focus is on air-driven grippers due to their ability to hold high payloads without causing visual and physical damage to the product. Key findings and conclusions Three pneumatic-based unilateral gripper principles, namely Coanda, Bernoulli and Vacuum, are critically reviewed for their feasibility in meat industry automation. In conclusion, the simple vacuum-based system offers the best solution of holding force and low damage thresholds. However, vacuum based design and adaption requires thought for meat surface and structure variance. This will inevitably lead to future experimental research and development work.A review of unilateral grippers for meat industry automationpublishedVersio

A design approach to a standard manipulator

New structures for gripping objects in robotic manipulation processes are oriented to the new arrangement of mechanical structures using new materials and processing technologies and innovative procedures for the implementation of contact gripping element links to an object with a high degree of adaptively of applications together with the ability to alter the structure of grip and limiting the intensity of the contact stiffness variation of snap elements custody and pliability. The application of elastomeric materials and surface finishes is important. This paper presents both a new gripper design for robot arms but also the search of the selected materials to make an experimental evaluation of technical parameters that are used to assess their application potential and suitability for the targeted applications. Also the results and conclusions for gripper testing in manipulation operations with two different robot arms are presented.Sellés Cantó, MÁ.; Pérez Bernabeu, E.; Sanchez-Caballero, S.; Cihlar, J. (2012). A design approach to a standard manipulator. Scientific Bulletin of "Petru Maior" Universityof Tîrgu-Mureş. 9(2):66-70. http://hdl.handle.net/10251/62593S66709

Soft Fingertips with Tactile Sensing and Active Deformation for Robust Grasping of Delicate Objects

Soft fingertips have shown significant adaptability for grasping a wide range of object shapes thanks to elasticity. This ability can be enhanced to grasp soft, delicate objects by adding touch sensing. However, in these cases, the complete restraint and robustness of the grasps have proved to be challenging, as the exertion of additional forces on the fragile object can result in damage. This paper presents a novel soft fingertip design for delicate objects based on the concept of embedded air cavities, which allow the dual ability of adaptive sensing and active shape changing. The pressurized air cavities act as soft tactile sensors to control gripper position from internal pressure variation; and active fingertip deformation is achieved by applying positive pressure to these cavities, which then enable a delicate object to be kept securely in position, despite externally applied forces, by form closure. We demonstrate this improved grasping capability by comparing the displacement of grasped delicate objects exposed to high-speed motions. Results show that passive soft fingertips fail to restrain fragile objects at accelerations as low as 0.1m/s2 , in contrast, with the proposed fingertips, delicate objects are completely secure even at accelerations of more than 5m/s2

Advances in soft grasping in agriculture

Agricultural robotics and automation are facing some challenges rooted in the high variability 9 of products, task complexity, crop quality requirement, and dense vegetation. Such a set of 10 challenges demands a more versatile and safe robotic system. Soft robotics is a young yet 11 promising field of research aimed to enhance these aspects of current rigid robots which 12 makes it a good candidate solution for that challenge. In general, it aimed to provide robots 13 and machines with adaptive locomotion (Ansari et al., 2015), safe and adaptive manipulation 14 (Arleo et al., 2020) and versatile grasping (Langowski et al., 2020). But in agriculture, soft 15 robots have been mainly used in harvesting tasks and more specifically in grasping. In this 16 chapter, we review a candidate group of soft grippers that were used for handling and 17 harvesting crops regarding agricultural challenges i.e. safety in handling and adaptability to 18 the high variation of crops. The review is aimed to show why and to what extent soft grippers 19 have been successful in handling agricultural tasks. The analysis carried out on the results 20 provides future directions for the systematic design of soft robots in agricultural tasks.Comment: Chapter 12 of the book entitled "Advances in agri-food robotics

Gripping devices of industrial robots for manipulating offset dish antenna billets and controlling their shape

Invention proposes an adaptive gripping device of an industrial robot, which combines functions of capturing different-shape manipulation objects with control of deviations from the shape of these objects. The device is a T-shaped frame with three Bernoulli grips pivotally mounted thereon and a pneumatic sensor. Analytical dependencies are presented for determination of design parameters of adaptive gripping device and calculation of required lifting force of each of Bernoulli Gripping Device (BGD). Formula is derived for determining its position of pneumatic sensor on frame of gripping devices. In the ANSYS-CFX software environment, numerical simulation of airflow dynamics in the gap between the cooperating BGD surfaces and the offset mirror antenna plate blank. The simulation was based on the Reynolds-Averaged Navier–Stokes (RANS) equations of viscous gas dynamics, the Shear Stress Transport (SST) model of turbulence, and the y model of laminar–turbulent transition. As a result of the simulation, the effect of the curvature radius of the surface of the plates of offset mirror antennas on the BGD power characteristics was determined

Review. Technologies for robot grippers in pick and place operations for fresh fruits and vegetables

[EN] Robotics has been introduced in industry to replace humans in arduous and repetitive tasks, to reduce labour costs and to ensure consistent quality control of the process. Nowadays robots are cheaper, can work in hostile and dirty environments and they are able to manipulate products at high speed. High speed and reliability and low robot gripper costs are necessary for a profitable pick and place (P&P) process. However, current grippers are not able to handle these products properly because they have uneven shapes, are flexible and irregular, have different textures and are very sensitive to being damaged. This review brings together the requirements and phases used in the process of manipulation, summarises and analyses of the existing, potential and emerging techniques and their possibilities for the manipulation of fresh horticultural products from a detailed study of their characteristics. It considers the difficulties and the lack of engineers to conceive of and implement solutions. Contact grippers with underactuated mechanism and suction cups could be a promising approach for the manipulation of fresh fruit and vegetables. Ongoing study is still necessary on the characteristics and handling requirements of fresh fruit and vegetables in order to design grippers which are suitable for correct manipulation, at high speed, in profitable P&P processes for industrial applications.This work has been partially funded by research project with reference DPI2010-20286 financed by the Spanish Ministerio de Ciencia e Innovacion.Blanes Campos, C.; Mellado Arteche, M.; Ortiz Sánchez, MC.; Valera Fernández, Á. (2011). Review. Technologies for robot grippers in pick and place operations for fresh fruits and vegetables. SPANISH JOURNAL OF AGRICULTURAL RESEARCH. 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Citrus postharvest diseases and injuries related to impact on packing lines. Scientia Agricola, 66(2), 210-217. doi:10.1590/s0103-90162009000200010Foglia, M. M., & Reina, G. (2006). Agricultural robot for radicchio harvesting. Journal of Field Robotics, 23(6-7), 363-377. doi:10.1002/rob.20131Garcı́a, J. L., Ruiz-Altisent, M., & Barreiro, P. (1995). Factors Influencing Mechanical Properties and Bruise Susceptibility of Apples and Pears. Journal of Agricultural Engineering Research, 61(1), 11-17. doi:10.1006/jaer.1995.1025Garcı́a-Ramos, F. ., Ortiz-Cañavate, J., & Ruiz-Altisent, M. (2004). Evaluation and correction of the mechanical aggressiveness of commercial sizers used in stone fruit packing lines. Journal of Food Engineering, 63(2), 171-176. doi:10.1016/s0260-8774(03)00297-8Grunert, K. G. (2005). Food quality and safety: consumer perception and demand. European Review of Agricultural Economics, 32(3), 369-391. doi:10.1093/eurrag/jbi011Han, I. (2007). 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(2007). Optimal grasp of vacuum grippers with multiple suction cups. Mechanism and Machine Theory, 42(1), 18-33. doi:10.1016/j.mechmachtheory.2006.02.007Menesatti, P., & Paglia, G. (2001). PH—Postharvest Technology. Journal of Agricultural Engineering Research, 80(1), 53-64. doi:10.1006/jaer.2000.0669Monta, M., Kondo, N., & Ting, K. C. (1998). Artificial Intelligence Review, 12(1/3), 11-25. doi:10.1023/a:1006595416751MORROW, C. T., & MOHSENIN, N. N. (1968). Dynamic Viscoelastic Characterization of Solid Food Materials. Journal of Food Science, 33(6), 646-651. doi:10.1111/j.1365-2621.1968.tb09093.xMuscato, G., Prestifilippo, M., Abbate, N., & Rizzuto, I. (2005). A prototype of an orange picking robot: past history, the new robot and experimental results. Industrial Robot: An International Journal, 32(2), 128-138. doi:10.1108/01439910510582255PELEG, M., & CALZADA, J. F. (1976). STRESS RELAXATION OF DEFORMED FRUITS AND VEGETABLES. 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Development of an expert system for supporting the selection of robot grippers

The aim of this thesis is to lay the basis for the development of an expert system for the selection of robot grippers. This work has started with a review of the literature of the grasping principles, of releasing strategies and of the main problems concerning the automatic assembly or, more in general, the handling. Later, we have studied a set of parameters constituting the input of the expert system, together with a set of rules aimed at choosing the appropriate gripper. The work ends with a series of tests, with a focus on the food industry, reporting the results and discussing the possibility of future developments

A Bernoulli principle gripper for handling of planar and 3D (food) products

Purpose – The purpose of this paper is the increase the flexibility of robots used for handling of 3D (food) objects handling by the development and evaluation of a novel 3D Bernoulli gripper. Design/methodology/approach – A new gripper technology have been designed and evaluated. A deformable surface have been used to enable individual product handling. The lift force generated and the force exerted on the product during gripping is measured using a material tester instrument. Various products are tested with the gripper. A experimental/theoretical approach is used to explain the results. Findings – A deformable surface can be used to generate a lift force using the Bernoulli principle on 3D objects. Using a small forming a significant increase in the lift force generated is recorded. Increasing the forming further was shown to have little or even negative effects. The forces exerted on the product during forming was measured to be sufficiently low to avoid product damage. Research limitations/implications – To be able to improve the grippers lift strength a better model and understanding of the flow is needed. Originality/value – A novel Bernoulli gripper for 3D Bernoulli gripping have been designed and evaluated. The gripper enables flexible and delicate handling of various product shapes, 3D as well as 2D. Increased utilization of robots in the food industry can be gained

Garras con sensores táctiles intrínsecos para manipular alimentos con robots

[EN] The primary handling of food with robots calls for the development of new manipulation devices, especially when products are easily damaged and have a wide range of shapes and textures. These difficulties are even greater in the agricultural industry because the quality of the products is also checked during the manual handling process. This PhD dissertation provides solutions to these issues and helps to further introduce robotics into the handling of food. Several methods for handling food are included and analyzed, and specific solutions are proposed and then validated with prototypes. The research focuses on devices capable of adapting themselves to the shapes of the products without increasing the complexity of the mechanism. After analyzing several different solutions, the method chosen involves the use of under-actuated mechanisms, compliant mechanisms and fingers with pads filled with granular fluids. These fluids can behave as quasi-liquids or quasi-solids due to the jamming transition, which provides a soft initial grasp and can support high stresses during fast movements performed by the robot. The additive manufacturing process provides an opportunity to develop robot grippers that are lighter, simpler, more flexible and cheaper. By using this process elastic mechanisms are manufactured in a single part, which are equivalent to mechanisms with several rigid parts connected by joints. Laser sintering is employed to produce pneumatic actuators, with different types of motions, based on the elastic properties of the materials used in this manufacturing process. As a result, the systems can be simplified to achieve grippers, with several fingers, that are produced as a single part. In order to estimate the freshness and quality of agricultural products while they are being grasped, accelerometers are added to the fingers of several grippers. Accelerometers are economical and act as intrinsic tactile sensors. They can be easily embedded, thereby reducing the risk of getting damaged due to contact with the product, and allow each of the grasping phases to be identified. To achieve good performance of the accelerometers, a specific process is defined for the robot gripper, which touches the products a few times. In addition, several gripper prototypes are manufactured with diverse under-actuated mechanisms, jamming systems, and a new program that processes the signals from the accelerometers using different procedures in order to obtain parameters that can be used to estimate the quality of products. These parameters are correlated with data from destructive tests that are commonly used as a reference. The best performance of the accelerometers is achieved when the finger employs a granular fluid, a correlation coefficient of 0.937 being accomplished for the ripeness of mangoes and 0.872 for the firmness of eggplants.[ES] La manipulación primaria de alimentos con robots precisa del desarrollo de nuevos sistemas de manipulación especialmente cuando los productos son sensibles al daño y presentan una amplia variabilidad de formas y texturas. En el sector agroalimentario las dificultades son aún mayores ya que la manipulación manual sirve además para inspeccionar los productos durante el proceso. Está tesis aporta soluciones a estos problemas facilitando la incorporación de la robótica. En la tesis se recopilan y analizan diversas soluciones para poder manipular alimentos proponiendo soluciones concretas que luego son validadas con prototipos. La investigación se centra en aquellos sistemas que son capaces de auto adaptarse a las formas de los productos sin incrementar la complejidad del mecanismo. Tras analizar diversas técnicas se propone el uso de mecanismos infra-actuados, mecanismos flexibles y dedos con fluidos granulares que, al estar encerrados dentro de una membrana, se comportan como cuasi-líquidos o cuasi-sólidos gracias a la transición jamming, permitiendo un agarre inicial suave y la posibilidad de transmitir esfuerzos elevados durante los movimientos del robot. En la búsqueda de garras más ligeras, sencillas, flexibles y económicas se aprovecha la oportunidad que brinda la tecnología de fabricación aditiva de material. Gracias a este proceso se fabrican mecanismos flexibles realizados en una única pieza y que equivalen a mecanismos de garras realizados con varias piezas rígidas unidos por articulaciones. Mediante el sinterizado por láser, se fabrican actuadores neumáticos, con diversos tipos de movimiento, basados en la flexibilidad del material empleado en su fabricación. En conjunto se simplifican los sistemas llegando a realizar garras flexibles de varios dedos fabricadas en una única pieza. Para evaluar la calidad y frescura de los productos agroalimentarios durante el agarre se emplean acelerómetros localizados en los dedos de varias garras. Los acelerómetros son económicos y se comportan como sensores táctiles intrínsecos, están fuera del contacto directo con el producto evitando desgastes por contacto y permiten identificar las distintas fases de agarre. Para lograr esto se desarrolla un proceso específico del robot con la garra, que palpa varias veces el producto. Se fabrican diversos tipos de garra con distintas tecnologías de mecanismos infra-actuados y sistemas jamming y se programa un algoritmo original de procesado de señal que con diversas técnicas es capaz de extraer parámetros de los acelerómetros que sirven para evaluar la calidad de los productos. Estos parámetros son correlacionados con los datos de ensayos destructivos que son habitualmente empleados como referencia. Las mejores capacidades se consiguen empleando garras con jamming lográndose coeficientes de correlación de 0.937 en índices de madurez con mangos y 0.872 en firmeza de berenjenas.[CA] La manipulació primària d'aliments amb robots precisa del desenvolupament de nous sistemes de manipulació especialment quan els productes són sensibles al dany i presenten una àmplia variabilitat de formes i textures. En el sector agroalimentari les dificultats són encara més grans ja que la manipulació manual serveix a més per a inspeccionar els productes durant el procés. Aquesta tesi aporta solucions a aquests problemes facilitant la incorporació de la robòtica. En la tesi es recopilen i analitzen diverses solucions per a poder manipular aliments proposant solucions concretes que després són validades amb prototips. La investigació es centra en aquells sistemes que són capaços d'auto adaptar-se a la forma dels productes sense incrementar la complexitat del mecanisme. Després d'analitzar diverses tècniques es proposa l'ús de mecanismes infra-actuats, mecanismes flexibles i dits amb fluids granulars que, tancats dins d'una membrana, es comporten com quasi-líquids o quasi-sòlids gràcies a la transició jamming, permetent una prensió inicial suau i la possibilitat de transmetre esforços elevats durant els moviments del robot. En la recerca d'urpes més lleugeres, senzilles, flexibles i econòmiques s'aprofita l'oportunitat que brinda la tecnologia de fabricació additiva de material. Gràcies a aquest procés es fabriquen mecanismes flexibles realitzats en una única peça i que equivalen a mecanismes d'urpes realitzats amb diverses peces rígides unides per articulacions. Mitjançant el sinteritzat per làser, es fabriquen actuadors pneumàtics, amb diversos tipus de moviment, basats en la flexibilitat del material emprat en la seva fabricació. En conjunt es simplifiquen els sistemes arribant a realitzar urpes flexibles de diversos dits fabricades en una única peça. Per a avaluar la qualitat i frescor dels productes agroalimentaris durant la manipulació s'empren acceleròmetres localitzats en els dits de diverses urpes. Els acceleròmetres són econòmics i es comporten com a sensors tàctils intrínsecs, sense estar en contacte directe amb el producte evitant desgastos per aquest motiu, i permeten identificar les diferents fases d'prensió. Per aconseguir això es desenvolupa un procés específic del robot amb l'urpa, que palpa diverses vegades el producte. Es fabriquen diversos tipus d'urpa amb diferents tecnologies de mecanismes infra-actuats i sistemes jamming i es programa un algoritme original de processat de senyal que, amb diverses tècniques, és capaç d'extreure paràmetres dels acceleròmetres que serveixen per a avaluar la qualitat dels productes. Aquests paràmetres són correlacionats amb les dades d'assajos destructius que són habitualment emprats com a referència. Les millors capacitats s'aconsegueixen emprant urpes amb jamming assolint-se coeficients de correlació de 0,937 en índexs de maduresa amb mangos i 0,872 en fermesa d'albergínies.Blanes Campos, C. (2016). Garras con sensores táctiles intrínsecos para manipular alimentos con robots [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68481TESI