scholarly journals Analysis of the Pneumatic System Parameters of the Suction Cup Integrated with the Head for Harvesting Strawberry Fruit

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4389
Author(s):  
Sławomir Kurpaska ◽  
Zygmunt Sobol ◽  
Norbert Pedryc ◽  
Tomasz Hebda ◽  
Piotr Nawara
Keyword(s):  
Testing Machine ◽  
Equivalent Diameter ◽  
Strawberry Fruit ◽  
Measurement Instruments ◽  
Suction Force ◽  
Practical Applications ◽  
Surface Areas ◽  
Suction Cup ◽  
Suction Cups ◽  
End Effectors

Fruit and vegetable harvest efficiency depends on the mechanization and automation of production. The available literature lacks the results of research on the applicability of pneumatic end effectors among grippers for the robotic harvesting of strawberries. To determine their practical applications, a series of tests was performed. They included the determination of the morphological indicators of the strawberry, fruit suction force, the real stress exerted by fruit suckers and the degree of fruit damage. The fruits’ morphological indicators included the relationships between the weight and geometrical dimensions of the tested fruit, the equivalent diameter, and the sphericity coefficient. The fruit suction force was determined on a stand equipped with a vacuum pump, and control and measurement instruments, as well as a MTS 2 testing machine. The necrosis caused by tissue damage to the fruits by suction cup adhesion was assessed by counting the necrosis surface areas using the LabView programme. The assessment of the necrosis was conducted immediately upon the test’s performance, after 24 and after 72h. The stress values were calculated by referring the values of the suction forces obtained to the surface of the suction cup face. The tests were carried out with three constructions of suction cups and three positions of suction cup faces on the fruits’ surface. The research shows that there is a possibility for using pneumatic suction cups in robotic picking heads. The experiments performed indicate that the types of suction cups constructions, and the zones and directions of the suction cups’ application to the fruit significantly affect the values of the suction forces and stresses affecting the fruit. The surface areas of the necrosis formed depend mainly on the time that elapses between the test and their assessment. The weight of strawberry fruit in the conducted experiment constituted from 13.6% to 23.1% of the average suction force.

scholarly journals Soft Hybrid Suction Cup Capable of Sticking to Various Objects and Environments

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 50
Author(s):  
Hideyuki Tsukagoshi ◽  
Yuichi Osada
Keyword(s):  
Vertical Direction ◽  
Check Valve ◽  
Adhesive Force ◽  
Outer Diameter ◽  
Shear Direction ◽  
Concrete Walls ◽  
Suction Force ◽  
Suction Cup ◽  
Valve Function ◽  
Suction Cups

A universal suction cup that can stick to various objects expands the areas in which robots can work. However, the size, shape, and surface roughness of objects to which conventional suction cups can stick are limited. To overcome this challenge, we propose a new hybrid suction cup structure that uses the adhesive force of sticky gel and the suction force of negative pressure. In addition, a flexible and thin pneumatic balloon actuator with a check valve function is installed in the interior, enabling the controllable detachment from objects. The prototype has an outer diameter of 55 mm, a weight of 18.8 g, and generates an adsorption force of 80 N in the vertical direction and 60 N in the shear direction on porous walls where conventional suction cups struggle to adsorb. We confirmed that parts smaller than the suction cup and fragile potato chips are adsorbed by the prototype. Finally, the effectiveness of the proposed method is verified through experiments in which a drone with the prototypes can be attached to and detached from concrete walls and ceilings while flying; the possibility of adsorption to dusty and wet plates is discussed.

A Self-Sealing Suction Cup Array for Grasping

2011 ◽  
Vol 3 (4) ◽  
Author(s):  
Chad C. Kessens ◽  
Jaydev P. Desai
Keyword(s):  
Large Range ◽  
Tensile Loading ◽  
Physical Contact ◽  
Element Analysis ◽  
Suction Force ◽  
Suction Cup ◽  
Wide Range ◽  
Suction Cups ◽  
The Cost

While suction technology was invented long ago, the application of suction to object manipulation thus far has been confined to many small, well-defined problem sets. Its potential for grasping a large range of unknown objects remains relatively unexplored. This paper introduces the design of a suction cup that is “self-sealing.” The suction cups comprising the grasper exert no suction force when the cup(s) are not in contact with an object, but instead exert suction force only when they are in physical contact with an object. Since grasping is achieved purely by passive means, the cost and weight associated with individual sensors, valves, and/or actuators are essentially eliminated. This paper presents the design, analysis, fabrication, and experimental results of an array of such self-sealing suction cups. Finite element analysis of the cup is shown for both compressive and tensile loading, and the quality of the internal seal is quantified. Finally, performance is shown to be comparable to that of a commercially available cup, and grasping capability is demonstrated on a wide range of objects.

scholarly journals Hydraulically Coupled Dielectric Elastomer Actuators for a Bioinspired Suction Cup

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3481
Author(s):  
Chi Zhang ◽  
Lei Liu ◽  
Kanghui Xu ◽  
Zhonghong Dong ◽  
Yuxi Ding ◽  
...  
Keyword(s):  
Stretch Ratio ◽  
Dielectric Elastomer ◽  
Compact Structure ◽  
Suction Force ◽  
Dc Voltage ◽  
Suction Cup ◽  
Dielectric Elastomer Actuators ◽  
Acrylic Plate ◽  
Suction Cups ◽  
Chamber Angle

Suction cups of cephalopods show a preeminent performance when absorbing irregular or flat objects. In this paper, an octopi-inspired suction cup, driven by hydraulically coupled dielectric elastomer actuators (HCDEAs), is proposed, which is considered to be controlled easily and have compact structure. To investigate the performance of suction cups, experiments have been conducted to clarify the effect of the pre-stretch ratio and chamber angle on suction forces. It could be seen that both factors have a complicated influence on suction forces, and the best performance obtained was a reasonable combination of the pre-stretch ratio and chamber angle. Here, we achieved a maximum suction force of 175 mN with λp = 1.2, α = 23° under a DC voltage of 3500 V. To enhance the capacity and adaptation of the suction cup, flat objects of various types of materials were introduced as targets. Experimental results displayed that for tested materials, including a dry/wet acrylic plate, CD, ceramic wafer, and aluminum plate, the suction cup showed outstanding performance of absorbing and lifting the target without any damage or scratch to them. Our research may serve as a guide to the optimal design and provide insights into the performance of the HCDEAs-actuated suction cup.

scholarly journals Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

10.5772/7228 ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 29 ◽  
Author(s):  
Hu Bing-Shan ◽  
Wang Li-Wen ◽  
Fu Zhuang ◽  
Zhao Yan-zheng
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Basic Structure ◽  
Thin Elastic Plate ◽  
Climbing Robots ◽  
Suction Cup ◽  
Sma Actuator ◽  
Suction Cups ◽  
Pressure Suction

Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA) are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME) extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

scholarly journals Synthesis, Characterization and Photocatalytic Activity of Nanocrystalline First Transition-Metal (Ti, Mn, Co, Ni and Zn) Oxisde Nanofibers by Electrospinning

2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Yu Chen ◽  
Weipeng Lu ◽  
Yanchuan Guo ◽  
Yi Zhu ◽  
Haojun Lu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transition Metal ◽  
Metal Oxide ◽  
Specific Surface ◽  
Three Dimensional ◽  
Photogenerated Electron ◽  
Practical Applications ◽  
Surface Areas ◽  
Tio2 Nanofiber ◽  
Transmission Electron

In this work, five nanocrystalline first transition-metal (Ti, Mn, Co, Ni and Zn) oxide nanofibers were prepared by electrospinning and controlled calcination. The morphology, crystal structure, pore size distribution and specific surface area were systematically studied by scanning electron microscope (SEM), transmission electron microscope (TEM), surface and pore analysis, and thermo gravimetric analyzer (TGA). The results reveal that the obtained nanofibers have a continuously twisted three-dimensional scaffold structure and are composed of neat nanocrystals with a necklace-like arrangement. All the samples possess high specific surface areas, which follow the order of NiO nanofiber (393.645 m2/g) > TiO2 nanofiber (121.445 m2/g) > ZnO nanofiber (57.219 m2/g) > Co3O4 nanofiber (52.717 m2/g) > Mn2O3 nanofiber (18.600 m2/g). Moreover, the photocatalytic degradation of methylene blue (MB) in aqueous solution was investigated in detail by employing the five kinds of metal oxide nanofibers as photocatalysts under ultraviolet (UV) irradiation separately. The results show that ZnO, TiO2 and NiO nanofibers exhibit excellent photocatalytic efficiency and high cycling ability to MB, which may be ascribed to unique porous structures and the highly efficient separation of photogenerated electron-hole pairs. In brief, this paper aims to provide a feasible approach to achieve five first transition-metal oxide nanofibers with excellent performance, which is important for practical applications.

scholarly journals A Pressing Attachment Approach for a Wall-Climbing Robot Utilizing Passive Suction Cups

Robotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 26
Author(s):  
Dingxin Ge ◽  
Yongchen Tang ◽  
Shugen Ma ◽  
Takahiro Matsuno ◽  
Chao Ren
Keyword(s):  
Experimental Test ◽  
Experimental Results ◽  
Climbing Robot ◽  
Guide Rail ◽  
Test Bed ◽  
Climbing Robots ◽  
Pressing Method ◽  
Suction Cup ◽  
Suction Cups

This paper proposes a pressing method for wall-climbing robots to prevent them from falling. In order to realize the method, the properties of the utilized suction cup are studied experimentally. Then based on the results, a guide rail is designed to distribute the attached suction cup force and implement the pressing method. A prototype of a wall-climbing robot that utilizes passive suction cups and one motor is used to demonstrate the proposed method. An experimental test-bed is designed to measure the force changes of the suction cup when the robot climbs upwards. The experimental results validate that the suction cup can completely attach to the surface by the proposed method, and demonstrate that the robot can climb upwards without falling.

Suction force evaluation of elliptical micro suction cup array

2017 ◽  
Vol 2017.8 (0) ◽  
pp. PN-28
Author(s):  
Hiromu Nakajima ◽  
Takeyoshi Dohi ◽  
Kenta Kuwana
Keyword(s):  
Suction Force ◽  
Suction Cup

Analysis of Power Relations in the Design of Effector for Unilateral Gripping with Active Vacuum Suction Cup

2014 ◽  
Vol 613 ◽  
pp. 286-291
Author(s):  
Peter Tuleja ◽  
Ľuboslava Šidlovská
Keyword(s):  
Power Relations ◽  
Vacuum Suction ◽  
Suction Cup ◽  
Suction Cups

This contribution present the process of projection of griping effector with active suction cups. It focuses on possible complication by solutions and estimates sequence of necessary calculations so that the designed gripper guarantied secure fixation of manipulated objects in time of handling work of robot.

Analysis of Flow Rates in the Design of Effector for Unilateral Gripping with Active Vacuum Suction Cup

2014 ◽  
Vol 613 ◽  
pp. 304-309
Author(s):  
Ľuboslava Šidlovská ◽  
Peter Tuleja
Keyword(s):  
Flow Rate ◽  
Vacuum Suction ◽  
Flow Rates ◽  
Suction Cup ◽  
Vacuum Generator ◽  
Suction Cups

This article deals with the problems of the need for the required volume and flow rate in the circuit with underpressure in the design of the gripping effector with active suction cups. It presents a process of designing a vacuum generator which is required to power such effector so that it guarantees a quick and secure fixation of handling objects (OM) at handling it with a robot. The article displays a means of determining of so-called evacuationtimes in the process of gripping of OM during the handling tasks.

scholarly journals Impacts of contracted endodontic cavities compared to traditional endodontic cavities in premolars

2020 ◽  
Author(s):  
Xia Juan ◽  
Wang weidong ◽  
Li Zhengmao ◽  
Lin Bingpeng ◽  
Zhang Qian ◽  
...  
Keyword(s):  
Root Canal ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Filling Material ◽  
Root Canal Filling ◽  
Surface Areas ◽  
Significant Difference ◽  
3D Printed ◽  
Post Hoc

Abstract Background: This study aims to compare the percentage of dentin removed, instrumentation efficacy, root canal filling and load at fracture between contracted endodontic cavities, and traditional endodontic cavities on root canal therapy in premolars. Methods: Forty extracted intact human first premolars were imaged with micro-CT and randomly assigned to the contracted endodontic cavity (CEC) or traditional endodontic cavity (TEC) groups. CEC was prepared with the aid of a 3D-printed template, canals were prepared with a 0.04 taper M-Two rotary instrument, and cavities were restored with resin. Specimens were loaded to fracture in an Instron Universal Testing Machine after a fatigue phase. The data were analyzed by the independent samples T test and Mann-Whitney U test, appropriate post hoc tests. Results: In the premolars tested in vitro, the percentage of dentin removed in the premolars with two dental roots in the CEC group (3.85% ± 0.42%) was significantly smaller (P < 0.05) than in the TEC group (4.94% ± 0.5%). The untouched canal wall (UCW) after instrumentation for TECs (16.43% ± 6.56%) was significantly lower (P< .05) than the UCW (24.42% ± 9.19%) for CECs in single-rooted premolars. No significant differences were observed in the increased canal volume and surface areas in premolars between the TEC and CEC groups (P > 0.05). CECs conserved coronal dentin in premolars with two dental roots but no impact on the instrument efficacy. There were no differences between the CEC groups and the TEC groups in the percentage of filling material and voids (P > 0.05). In addition, the mean load at failure of premolars did not significantly differ between the CEC and TEC groups and there was no significant difference in the type of fracture (P > 0.05). Conclusion: The results of this study suggest that CEC could not improve the fracture resistance of the endodontically treated premolars. The instrumentation efficacy and the percentage of filling material did not significantly differ between CECs and TECs in premolars. Keywords: 3D-printed template, contracted endodontic cavities, instrumentation efficacy, root canal filling, fracture resistance

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