Development of a Robot for Evaluating Tennis Rackets

2001 ◽  
Vol 13 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Junji Furusho ◽  
◽  
Masamichi Sakaguchi ◽  
Naoyuki Takesue ◽  
Fuminobu Sato ◽  
...  

The development and simulation of robots that have athletic skill close to human beings is very much useful for testing and developing sport goods. This paper discusses the development and simulation of a tennis robot. The developed tennis robot has two joints controlled by a servolike human muscle, and its characteristics are satisfying and similar to a human. The simulation for the whole system including racket, ball and tennis robot is set up. The simulation results agree well with experimental results.

2013 ◽  
Vol 423-426 ◽  
pp. 2026-2034 ◽  
Author(s):  
Hong Xing Gao ◽  
Mao Ru Chi ◽  
Min Hao Zhu ◽  
Ping Bo Wu

Three accurate dynamic model of air spring was set up through aerodynamics, fluid mechanics, structural mechanics,engineering thermodynamics, etc. According to the new established bellow-orifice-reservoir model, bellow-pipe-reservoir model and bellow-orifice-pipe-reservoir model, the dynamic characteristics of air spring were calculated under different excitation amplitudes and frequencies. By comparison with experimental results, it shows that the simulation results of the three models and experimental results coincide very well in dynamic characteristics; the bellow-orifice-pipe-reservoir connection type is recommended as the secondary suspension for low frequency excitations; and the bellow-orifice-reservoir connection type is considered effectively for high frequency excitations; the bellow-pipe-reservoir connection type is not recommended to be used as the secondary suspension because of its negative stiffness.


2018 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Mohammad Ahashan ◽  
Dr. Sapna Tiwari

Man has always tried  to determine  and tamper the image of woman and especially her identity is manipulated and orchestrated. Whenever a woman is spoken of, it is always in the relation to man; she is presented as a wife , mother, daughter and even as a lover but never as a woman  a human being- a separate entity. Her entire life is idealized and her fundamental rights and especially her behaviour is engineered by the adherents of patriarchal society. Commenting  on the Man-woman relationship in a marital bond Simone de Beauvoir wrote in her epoch-making book entitled The Second Sex(1949): "It has been said that marriage diminishes man,  which is often true , but almost always it annihilates women". Feminist movement advocates the equal rights and equal opportunities for women. The true spirit of feminism is into look at women and men as human beings. There should not be gender bias or discrimination in familial and social life. To secure gender justice and gender equity is the key aspects of feminist movement. In India, women writers have come forward to voice their feminist approach to life and the patriarchal family set up. They believe that the very notion of gender is not only biotic and biologic episode but it has a social construction.


Author(s):  
N. Thyagaraju

The present seminar paper mainly highlight  the concept of  water pollution, causes of water pollution,  Its Effects, Elements of  pollutants, Methods  used to prevent the water pollution in environment  and the mandatory initiatives taken by the concerned authorities for prevention of  water pollution. Water   is essential for survival of all living organisms on the earth. Thus for human beings and plants to survive on land, water should be easily accessible. The term “Pollution” is generally refers to addition of any foreign body either living or non – living or deletion of anything that naturally exists. The basic Sources of Water pollution causes due to Culmination into lakes, rivers, ponds, seas, oceans etc. Domestic drainage and sanitary waste, Industrial drainage and sewage, Industrial waste from factories, Dumping of domestic garbage, Immersion of Idols made of plaster of Paris, Excess use of Insecticides , pesticides, fungicides, Chemical fertilizers, Soil erosion during heavy rains and floods, Natural disasters, tsunami etc. General pollutants  which are also caused for water pollution  which include Organic, Inorganic, and Biological entities, Insecticides, Pesticides, Disinfectants ,Detergents, Industrial solvents, Acids, Ammonia fertilizers, heavy metals, Harmful bacteria, Virus, Micro –Organisms and worms, Toxic chemicals. Agricultural lands become infertile and thereby production also drops, Spread of epidemic diseases like Cholera, Dysentery, Typhoid, Diarrhea, Hepatitis, Jaundice etc. The  basic responsibility of the Government, NGOs, National Pioneer scientific Research Institutions may conduct  research oriented programs on control of water pollution by create  awareness among the public through mass media and Environmental Education on recycling units,  and  water treatment plants must be established both at domestic levels and Industry levels, Every citizen must feel responsible to control water pollution. There have been many water pollution prevention acts that have been set up by the governments of the world. But these are not enough for permanent water pollution solutions. Each of us needs to take up the responsibility and do something at an everyday at individual level. Otherwise we can’t survive in a society forever in a future. 


2014 ◽  
Vol 945-949 ◽  
pp. 777-780
Author(s):  
Tao Liu ◽  
Yong Xu ◽  
Bo Yuan Mao

Firstly, according to the structure characteristics of precision centrifuge, the mathematical model of its dynamic balancing system was set up, and the dynamic balancing scheme of double test surfaces, double emendation surfaces were established. Then the dynamic balance system controller of precision centrifuge was designed. Simulation results show that the controller designed can completely meet the requirements of precision centrifuge dynamic balance control system.


2021 ◽  
pp. 004051752098812
Author(s):  
Xixi Qian ◽  
Yuanying Shen ◽  
Qiaoli Cao ◽  
Jun Ruan ◽  
Chongwen Yu

A simulation describing the fiber movement during the condensation was conducted, and the effect of the condensation in the carding machine was studied. The simulation results showed that the condensation has the blending and the evening effect on the condensed sliver, which can be explained by the fiber rearrangement. Moreover, the increasing web width and the decreasing condensing length can result in a more uniform sliver. Further, the evening effect of the web width on the web was verified by experiments. The simulation results were in general agreement with the experimental results.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 288
Author(s):  
Adam Wolniakowski ◽  
Charalampos Valsamos ◽  
Kanstantsin Miatliuk ◽  
Vassilis Moulianitis ◽  
Nikos Aspragathos

The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.


Author(s):  
Yanxia Li ◽  
Zhongliang Liu ◽  
Yan Wang ◽  
Jiaming Liu

A numerical model on methane/air combustion inside a small Swiss-roll combustor was set up to investigate the flame position of small-scale combustion. The simulation results show that the combustion flame could be maintained in the central area of the combustor only when the speed and equivalence ratio are all within a narrow and specific range. For high inlet velocity, the combustion could be sustained stably even with a very lean fuel and the flame always stayed at the first corner of reactant channel because of the strong convection heat transfer and preheating. For low inlet velocity, small amounts of fuel could combust stably in the central area of the combustor, because heat was appropriately transferred from the gas to the inlet mixture. Whereas, for the low premixed gas flow, only in certain conditions (Φ = 0.8 ~ 1.2 when ν0 = 1.0m/s, Φ = 1.0 when ν0 = 0.5m/s) the small-scale combustion could be maintained.


2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.


2011 ◽  
Vol 199-200 ◽  
pp. 597-602
Author(s):  
Shou Fa Liu ◽  
Zhang Jie Shi ◽  
Chun Feng Li

In this paper, the overall design of magnetic levitated thrust bearing experiment table was completed, of which the main experimental parameters those are electromagnetic parameters and structural dimensions were determined, in addition, the joint debugging and deformation measurement are performed. Analysis results showed that theoretical value, ANSYS simulation results and experimental results were similar, which said that it is feasible to perform stiffness check of the thrust collar on the experiment table.


2018 ◽  
Vol 22 (8) ◽  
pp. 4425-4447 ◽  
Author(s):  
Manuel Antonetti ◽  
Massimiliano Zappa

Abstract. Both modellers and experimentalists agree that using expert knowledge can improve the realism of conceptual hydrological models. However, their use of expert knowledge differs for each step in the modelling procedure, which involves hydrologically mapping the dominant runoff processes (DRPs) occurring on a given catchment, parameterising these processes within a model, and allocating its parameters. Modellers generally use very simplified mapping approaches, applying their knowledge in constraining the model by defining parameter and process relational rules. In contrast, experimentalists usually prefer to invest all their detailed and qualitative knowledge about processes in obtaining as realistic spatial distribution of DRPs as possible, and in defining narrow value ranges for each model parameter.Runoff simulations are affected by equifinality and numerous other uncertainty sources, which challenge the assumption that the more expert knowledge is used, the better will be the results obtained. To test for the extent to which expert knowledge can improve simulation results under uncertainty, we therefore applied a total of 60 modelling chain combinations forced by five rainfall datasets of increasing accuracy to four nested catchments in the Swiss Pre-Alps. These datasets include hourly precipitation data from automatic stations interpolated with Thiessen polygons and with the inverse distance weighting (IDW) method, as well as different spatial aggregations of Combiprecip, a combination between ground measurements and radar quantitative estimations of precipitation. To map the spatial distribution of the DRPs, three mapping approaches with different levels of involvement of expert knowledge were used to derive so-called process maps. Finally, both a typical modellers' top-down set-up relying on parameter and process constraints and an experimentalists' set-up based on bottom-up thinking and on field expertise were implemented using a newly developed process-based runoff generation module (RGM-PRO). To quantify the uncertainty originating from forcing data, process maps, model parameterisation, and parameter allocation strategy, an analysis of variance (ANOVA) was performed.The simulation results showed that (i) the modelling chains based on the most complex process maps performed slightly better than those based on less expert knowledge; (ii) the bottom-up set-up performed better than the top-down one when simulating short-duration events, but similarly to the top-down set-up when simulating long-duration events; (iii) the differences in performance arising from the different forcing data were due to compensation effects; and (iv) the bottom-up set-up can help identify uncertainty sources, but is prone to overconfidence problems, whereas the top-down set-up seems to accommodate uncertainties in the input data best. Overall, modellers' and experimentalists' concept of model realism differ. This means that the level of detail a model should have to accurately reproduce the DRPs expected must be agreed in advance.


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