A Self-Sealing Suction Cup Array for Grasping

2011 ◽  
Vol 3 (4) ◽  
Author(s):  
Chad C. Kessens ◽  
Jaydev P. Desai

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.

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 50
Author(s):  
Hideyuki Tsukagoshi ◽  
Yuichi Osada

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.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4389
Author(s):  
Sławomir Kurpaska ◽  
Zygmunt Sobol ◽  
Norbert Pedryc ◽  
Tomasz Hebda ◽  
Piotr Nawara

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.


2020 ◽  
Vol 47 (3) ◽  
pp. 265-283
Author(s):  
Douglas Murphy ◽  
Denise Lester ◽  
F. Clay Smither ◽  
Ellie Balakhanlou

Neuropathic pain (NP) can have either central nervous system causes or ones from the peripheral nervous system. This article will focus on the epidemiology, classifications, pathology, non-invasive treatments and invasive treatments as a general review of NP involving the peripheral nervous system. NP has characteristic symptomatology such as burning and electrical sensations. It occurs in up to 10% of the general population. Its frequency can be attributed to its occurrence in neck and back pain, diabetes and patients receiving chemotherapy. There are a wide range of pharmacologic options to control this type of pain and when such measures fail, numerous interventional methods can be employed such as nerve blocks and implanted stimulators. NP has a cost to the patient and society in terms of emotional consequences, quality of life, lost wages and the cost of assistance from the medical system and thus deserves serious consideration for prevention, treatment and control.


Author(s):  
Ігор Борохвостов ◽  
Микола Білокур ◽  
Євген Колотухин ◽  
Іван Ткач

Maintenance of samples of weapons is carried out at the stages of their life cycle and is carried out on the basis of coordination of actions of the customer and the consumer with a wide range of organizations from the main developer to the co-executors, which does not exclude the occurrence of conflict situations. This leads to the problem of implementing the optimal synthesis of such a complex system and does not allow to direct efforts to achieve the extremum of the target function of the system as a whole. Therefore, the emergence of such a problem and the existing conflicts in the process of determining the means of providing arms to military formations is considered as a complex organizational system, and the difficulties of direct solution of the problem of optimal synthesis in this case are related to: the interconnections of a complex system (between systems of the lower level and elements of the system); limited programming abilities; the construction of a mathematical model, etc.; and cause the need to find solutions to this problem. The methods developed at present allow analytically to calculate the technical perfection of the weapons samples that are considered for providing military formations, as investigated when choosing for procurement or development. Such tasks are deterministic, but, considering costs at all stages of the life cycle, there may be stochastic (probable ones) that can be solved by expert methods. At present, the list and content of the source data when choosing ways of providing weapons are not defined at all stages. Thus, having them strictly non-formalized, the statement of the problem of synthesis is carried out under conditions of uncertainty, which in most cases is solved by heuristic methods, which in turn allows elements of subjectivity. Having determined the list and content of the initial data, it is possible to pre-implement the calculations in cost form (strictly mathematical) in the form of expenses, having carried out the projection of expenditures at the stage of the weapon’s life cycle, and such a list to be chosen according to the criterion of the problem of synthesis, while defining the criteria of the restrictions, and to use these data for assessing the quality of this type of weapons and the cost of the stages of their life cycle. Also, in case of incomplete receipt of such data in cost form, with their partial, such an assessment will allow to determine between the corresponding methods when solving the problem of choosing ways of providing arms in the medium term. Even if this method is not analytical, then the relevant statistics will help to reduce the degree of uncertainty and subjectivism when choosing ways to provide armed skills by expert means.


2020 ◽  
Author(s):  
Anna Nowakowska ◽  
Alasdair D F Clarke ◽  
Amelia R. Hunt ◽  
Jacqueline von Seth

When searching for an object, do we minimize the number of eye movements we need to make? Under most circumstances, the cost of saccadic parsimony likely outweighs the benefit, given the cost is extensive computation and the benefit is a few hundred milliseconds of time saved. Previous research has measured the proportion of eye movements directed to locations where the target would have been visible in the periphery, as a way of quantifying the proportion of superfluous fixations. A surprisingly large range of individual differences has emerged from these studies, suggesting some people are highly efficient and others much less so. Our question in the current study is whether these individual differences can be explained by differences in motivation. In two experiments, we demonstrate that neither time pressure, nor financial incentive, led to improvements of visual search strategies; the majority of participants continued to make many superfluous fixations in both experiments. The wide range of individual differences in efficiency observed previously was replicated here. We observed small but consistent improvements in strategy over the course of the experiment (regardless of reward or time pressure) suggesting practice, not motivation, makes participants more efficient.


Author(s):  
Luis Escobar

As a practicing statistician, we frequently are asked questions like: What is the role of statistics in our daily life? Why do we need statistics? What would the world be without statistics? Here are some of my thoughts on these and related matters. Statistics is an ancient tool which has been useful in solving problems of interest and understanding the world we live in. Until recently, say 60 years ago, in Latin America there was the wrong perception that statistics was an exoteric field that did not relate well to the needs of our society. Also, it was incorrectly thought that statistics was a branch of mathematics of interest only to people in academia. Fortunately, the perception is changing. These days, we find more and more people interested on how and where one could use statistics to the advantage of government, business, sciences, and day to day affairs. Careers and training in statistics are becoming more common in our universities, and statisticians are beginning to play an important role in our society. Statistics derives its power from the positive impact that it can have when it interacts with other fields like science, business, government, services, and research in general. There are numerous well documented reports for the interdisciplinary added value due to the use of statistics. The reports are on a wide range of applications from Physics (see, Mahon, B. “How Science Got Statistics”, Significance, June 2015) to improving the quality of beer (see, https:// en.wikipedia.org/wiki/William_Sealy_Gosset). For a very interesting collection of applications in México, see http://www. mundoestadisticacimat.mx/videos. In principle the idea is to use statistics to make decisions based on uncertainty and limited information. The first hurdle to overcome is to agree to the concept that basically there are no predictable or repeatable processes. That variability is inherent on whatever we observe, measure, or manufacture. Also, to understand that it is unrealistic to expect a complete control of variability, if at all possible, at a reasonable cost. In making decisions under uncertainty there are important considerations: The risk in simplistic terms is function of the probability that the decision is incorrect and the cost due to the incorrect decision. If the risk is too high, it might be the case that we should not assume the risk or take action to decrease the probability or cost (or both) of an incorrect decision. Related, suppose that there is a business decision which carries minor lasting economic repercussions in case of failure, other than the cost of implementing it, but with great competitive advantages if it succeeds. The business opportunity is a function of the probability of a successful decision and the benefits derived from this decision. If the investment to try the new venture is low as compared to potential business opportunity, why not try? In either case, getting a good estimate of the probability of an incorrect (or correct) decision is in the realm of work where good statistics combined with subject matter is paramount. Interestingly, statistics thrives in moments of crisis. The need of quick response or understanding of undesirable events has shown the important role of statistics in those decision making situations. A few documented cases that come to mind are: the important work of statisticians in breaking the Enigma code and the developing of the A-bomb during World War II, the role of statistics in understanding the problem and finding adequate treatments for HIV patients since this epidemiologic crisis emerged in the 1980s, understanding the root cause for the Space Shuttle Challenger disaster in 1986, and the work of statisticians in the non-destructive evaluation area caused by the current terrorist attacks. Of course, all these examples are high end applications, but statistics is being used today for more mundane purposes like: what is the remaining life of the battery of a pacemaker that a patient has worn for a certain period of time or how to identify those students in their first college year with the highest probability of abandoning their college education. Another important trait of statistics is its evolving nature. It is a field in the making in the sense that the field is driven by change and innovations (i.e., the discipline grows due to the needs of new problems to solve). We have the challenge and opportunity of forging and building statistical curricula that is useful for our future graduates. Where should we start? This is subject to debate. I am of the opinion that it should be started at the high school level at the latest, but by all means all college students should be exposed to some type of statistics education. Not everybody needs to be a practicing statistician, but at the very minimum, individuals in decision making positions should know when to use statistics or when to bring in statisticians into the decision making process. Paraphrasing A. Gelman, what would be “A world without statistics?” Well, the world most likely would have not disappeared, but we would not understand it so well, it would not be as confortable, and the quality of life would not be as good. Finally, for young generations interested in jobs for the future, the track record of statistics in other countries anticipates that in Latin America statistics would be a promising career with good job security, competitive salaries, and friendly working environments.


2021 ◽  
Author(s):  
Moataz Dowaidar

Nanomedicines are being tasked with boosting the efficacy of existing immunotherapies. Understanding the pathophysiology of the targeted tumors is critical for devising the optimum strategy. The corticosteroid dexamethasone has recently been discovered to promote tumor perfusion and nanomedicine accumulation. Only a limited percentage of patients, however, respond to immune checkpoint blockage (ICB). In the United States, for example, it is believed that ICB therapy is ineffective for about 87 percent of cancer patients. The care of enhanced permeability and retention (EPR)-stratified patients has the potential to improve treatment outcomes. Treating patients with several metastatic foci with varying amounts of EPR impact could increase nanomedicine impact in cancer patients, but only losartan has yet to reach clinical trials. Other medication repurposing techniques have been proposed for the increased efficacy of small medicines and antibodies, but they are still in clinical trials and need to be tested in human patients. The treatment of these patients could improve the effectiveness of nanomedi-based immunotherapy and reduce the toxicity of chemotherapy and radiation therapy. This could have a positive effect on cancer patients' survival rates and quality of life, as well as on the cost of treatment. The potential of nanomedicines to deliver a wide range of immunomodulating drugs and modulate their action in space


2020 ◽  
pp. 1-11
Author(s):  
Sheetal D. Gunjal ◽  
Rajeshree D. Raut ◽  
Abhay Wagh

The paper presents integration of Discrete Wavelet Cosine Transform technique and Bacterial Foraging Algorithm (BFO) for the development and optimization of speech coder. It is depicted how by filtering the limited number of high energy components of transformed coefficients with parallel programming can maintain the speech signal quality in coding over wide range of bit rates. The performance of existing and proposed speech coding techniqueattributes such as compression ratio, coding delay, computational complexity and quality of reconstructed speech is examined for multiple bit rates and compared with other existing speech coding techniques in Matlab environment. The result showsimprovement in performancewith respect to all attributes at the cost of increase in complexity.


2020 ◽  
Vol 978 ◽  
pp. 323-329
Author(s):  
Krishnendu Bhowmik ◽  
Shamim Akhtar ◽  
Raj Kumar Kalshyan ◽  
Niloy Khutia ◽  
Amit Roy Choudhury

The present study is mainly aimed at investigating the distribution of in-plane stresses of a rectangular plate under localized uniform in-plane tensile loading through finite element analysis. The configuration used in the analysis is analogous to the case of premature failure of stiffened panel due to the termination of a stiffener in aircraft wing structure. In this current work, three different types of materials namely, isotropic, plain woven and transversely isotropic materials are being considered. Aluminium is taken as isotropic; high strength carbon/epoxy is being assigned as plain woven composite and carbon nanotube based hybrid composite is used as transversely isotropic material, due to their wide range of applications in aircraft structures. The effect of different materials on overall axial, transverse and shear stress distributions at different layers of the stiffened composite panels are demonstrated using finite element analyses. Further, the variations of these stresses along axial and transverse directions are also compared for different materials. It can be concluded from the present study that the peak stress developed near the load application zone should be incorporated in the design criteria of such plates to avoid failure.


2013 ◽  
Vol 457-458 ◽  
pp. 1283-1287 ◽  
Author(s):  
Si Ling Feng ◽  
Qing Xin Zhu ◽  
Sheng Zhong ◽  
Xiu Jun Gong

Biogeography-based optimization (BBO) is a new biogeography inspired algorithm. It mainly uses the biogeography-based migration operator to share the information among solution. Differential evolution (DE) is a fast and robust evolutionary algorithm for global optimization. In this paper, we applied a hybridization of adaptive BBO with DE approach, namely ABBO/DE/GEN, for the global numerical optimization problems. ABBO/DE/GEN adaptively changes migration probability and mutation probability based on the relation between the cost of fitness function and average cost every generation, and the mutation operators of BBO were modified based on DE algorithm and the migration operators of BBO were modified based on number of iteration to improve performance. And hence it can generate the promising candidate solutions. To verify the performance of our proposed ABBO/DE/GEN, 9 benchmark functions with a wide range of dimensions and diverse complexities are employed. Experimental results indicate that our approach is effective and efficient. Compared with BBO/DE/GEN approaches, ABBO/DE/GEN performs better, or at least comparably, in terms of the quality of the final solutions and the convergence rate.


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