There are two main categories of force control schemes: hybrid position-force control and impedance control. However, the former does not take into account the dynamic interaction between the robot’s end effector and the environment. In contrast, impedance control includes regulation and stabilization of robot motion by creating a mathematical relationship between the interaction forces and the reference trajectories. It involves an energetic pair of a flow and an effort, instead of controlling a single position or a force. A mass-spring-damper impedance filter is generally used for safe interaction purposes. Tuning the parameters of the impedance filter is important and, if an unsuitable strategy is used, this can lead to unstable contact. Humans, however, have exceptionally effective control systems with advanced biological actuators. An individual can manipulate muscle stiffness to comply with the interaction forces. Accordingly, the parameters of the impedance filter should be time varying rather than value constant in order to match human behavior during interaction tasks. Therefore, this paper presents an overview of impedance control strategies including standard and extended control schemes. Standard controllers cover impedance and admittance architectures. Extended control schemes include admittance control with force tracking, variable impedance control, and impedance control of flexible joints. The categories of impedance control and their features and limitations are well introduced. Attention is paid to variable impedance control while considering the possible control schemes, the performance, stability, and the integration of constant compliant elements with the host robot.
In this work Polyynes was synthesized by pulse laser ablation of graphite target in ethanol solution. UV-Visible Spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR) and Transmission electron microscopy (TEM) were used to study the optical absorption, chemical bonding, particle size and the morphology. UV absorption peaks coincide with the electronic transitions corresponding to linear hydrogen – capped polyyne (Cn+1H2), the absorption peaks intensity increased when the polyynes were produced at different laser energies and the formation rats of polyynes increased with the increasing of laser pulse number. The FTIR absorption peak at 2368.4 cm-1, 1640.0 cm-1 and 1276.
... Show MoreThe ulma is one of the most spread social phenomenon.It occupies people in their different tendencies,the ulma imposes itself strongly in their social ,economic and politic sidies.
The problem of freedom quarrel is the older problem in creation .The groups as well as the individuals look for their liberty and it is restricted, they isolate themselves from others for a achieving it. Isolation phenomenon is one of common humanity phenomenon among individuals for looking of individuals psychological and social compatibility with other and society so they feel anxiety and tension and restriction of will and freedom. IT is known that college student from the major never in development and ren
... Show MoreThe filler in the asphalt mixture is essential since it plays a significant role in toughening and stiffening the asphalt. Changes in filler type can lead the asphalt mixtures to perform satisfactorily during their design life or degrade rapidly when traffic and environmental effects are considered. This study aims to assess the impact of filler types such as limestone dust (LS) and hydrated lime (HL) on Marshall characteristics and moisture damage in asphalt mixtures. Three different percentages of HL were employed in this study to partially replace the LS mineral filler: 1.5, 2.0, and 2.5% by aggregate weight. Furthermore, a control mixture was created with 7% LS by overall aggregate weight for the wearing course layer. The Marsha
... Show Moreالحمدُ للهِ رب العالمين ، والصلاة والسلام على نبيه الأمين محمد r وعلى آله الطيبين الطاهرين ، وأصحابه الغر الميامين:
تعد الصورة السمعية مفهوما بيانيا نجده في البلاغة العربية واضحاً مؤثرا، مؤديا دورا جوهريا في إيصال الفكرة التي يروم الأديب إيصالها إلى المتلقي ولا تبدو السمعية واضحة إلاّ إذا نظر إليها في حالة أدبيه تهز كيان الشاعر  
... Show MoreIn search of novel antibacterial agent, a series of new isatin derivatives (3a-d) have been synthesized by condensation isatin (2,3-indolinendione) with piperidine (hexahydropyridine), hydrazine hydrate and Boc-amino acids respectively. Compounds synthesized have been characterized by IR spectroscopy and elemental analysis. In addition, the in vitro antibacterial properties have been tested against E. coli, P. aeruginosa, and Bacillus cereus, S. aureus by employing the well diffusion technique. A majority of the synthesized compounds were showing good antibacterial activity and from comparisons of the compounds, compound 3d has been determined to be the most active compound.
The study aimed to identification the effect of brainstorming in linguistically grow of garten child the sample of study is composed from (48)male and female children have been distributed for two groups,one of them is experimental and another is disciplined for every per of garten and pre education,and they have been awarded in a number of variations. For measuring the subordinate variation(linguistically grow)the researcher prepared ascale for this purpose that consist of two parts:the first part the scale of linguistically grow of garten child(4-5 years)and the second part the scale of linguistically grow of pre education child (5-6 years).Consist of every one from (20)shapes of linguistically grow shapes for garten chil
... Show MoreBackground: Oral health is important to the quality of life of all individuals. Oral lesions can cause discomfort or pain that interferes with mastication, swallowing, and speech. Oral disease is a health problem that is not only a matter of oral hygiene and local condition, but can also be a precursor to other dangerous and potentially life threatening illnesses. The present study was designed to analyze the main clinicopathological aspects of most common oral lesions in patients who visit the Oral Diagnosis Clinic of the College of Dentistry, University of Sulaimani, Kurdistan region, Iraq. Patients and methods: This prospective study was performed on 3144 patients from July 2009-July 2010. In this study a total of 3144 patients were e
... Show MoreThe present research aims to measure the wisdom among university students and the differences of the concept of wisdom according to the gender of students in college of Basic Education. The sample of the research reached (300) male and female students in the morning studies upon the four stages of the psychological guidance department, the Scale of wisdom has been designed by the researcher herself and the psychometric feature were obtained as validity and Reliability. the researcher used Chi- square to Know the differences between the number of agreed and disagreed students for the wisdom scale, as well as the researcher used person correlation coefficient to Know the reliability of the scale by re test method for wisdom scale , t- test
... Show MoreThis paper deals with a dilapidated urban part with a proposal to renew it and return it to the life cycle of the city, as in the neighborhood of Al-Mdawar, adjacent to the port of Beirut. It discusses the challenges and the need for renewal, the causes of urban deterioration, the urban development approach and the history of the regulations applied to Beirut, In the studied area. It also proposes solutions to improve its lifestyle based on urban planning tools and design to achieve people's aspirations, preserve identity and rearrange its integration with the Beirut central district area.