Preferred Language
Articles
/
Zxem7ZEBVTCNdQwCfJy0
Hierarchical Stabilization and Tracking Control of a Flexible-Joint Bipedal Robot Based on Anti-Windup and Adaptive Approximation Control
...Show More Authors

Bipedal robotic mechanisms are unstable due to the unilateral contact passive joint between the sole and the ground. Hierarchical control layers are crucial for creating walking patterns, stabilizing locomotion, and ensuring correct angular trajectories for bipedal joints due to the system’s various degrees of freedom. This work provides a hierarchical control scheme for a bipedal robot that focuses on balance (stabilization) and low-level tracking control while considering flexible joints. The stabilization control method uses the Newton–Euler formulation to establish a mathematical relationship between the zero-moment point (ZMP) and the center of mass (COM), resulting in highly nonlinear and coupled dynamic equations. Adaptive approximation-based feedback linearization control (so-called adaptive computed torque control) combined with an anti-windup compensator is designed to track the desired COM produced by the high-level command. Along the length of the support sole, the ZMP with physical restrictions serves as the control input signal. The viability of the suggested controller is established using Lyapunov’s theory. The low-level control tracks the intended joint movements for a bipedal mechanism with flexible joints. We use two control strategies: position-based adaptive approximation control and cascaded position-torque adaptive approximation control (cascaded PTAAC). The interesting point is that the cascaded PTAAC can be extended to deal with variable impedance robotic joints by using the required velocity concept, including the desired velocity and terms related to control errors such as position, force, torque, or impedance errors if needed. A 6-link bipedal robot is used in simulation and validation experiments to demonstrate the viability of the suggested control structure.

Scopus Clarivate Crossref
View Publication
Publication Date
Mon Jul 01 2013
Journal Name
Political Sciences Journal
Democracy and human security
...Show More Authors

Since the widespread use of the concept of human security in 1994, and as stated in the report of human development (UNDP) issued by the United Nations Development Programmer,And framed it with multiple dimensions of political, economical, social and cultural. This concept has became beyond the state and its security ,and covered all what, can threaten human life and humanitarian groups, according to the humanitarian needs in the following aspects: The economic, the food,health,environmental , individual, community and the political aspect,which totally means ,the disability of the security traditional perspective to deal with these issues.The achievement of human security,that handles the maintenance of human dignity for meeting their b

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 22 2024
Journal Name
Al–bahith Al–a'alami
Television and Agenda Building
...Show More Authors

Most media studies on the development of the agenda have focused on the relationship between the content of the media and the audience of these media, and the extent of its impact on the agenda of the media, in addition to comparing it to the extent of interest in the agenda of those means. While in the construction of the agenda, we focus on the relationship between news sources and the media and the role of these sources in the process Building the agenda.These sources are institutions, parties, pressure groups, interest groups, the head of state and other media. The impact of these sources on the process of building the agenda are shown through the process of the selection of resources by the channel and communicators, and the technic

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
The Gender and Society
...Show More Authors

0

View Publication Preview PDF
Publication Date
Sun Apr 03 2005
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Gastrintestinal Manifestation and Alcoholic
...Show More Authors

Background: Alcohol remains the single most significant Cause of liver disease throughout the Western World, responsible for between 40 and 80% of cases of cirrhosis in different countries. Many of the factors underlying the development of alcoholic liver injwy remain unknown, and significant questions remain about the value of even very basic therapeutic strategies.
Patients and Methods: A total number of 113 patients with ALD attending the Gastroenterology and Hepatology teaching hospital between December 2001 and December 2003 were studied for the gastrointestinal, esophagogastroduodenoscopic manifestation of alcoholic liver disease.
Results.'The most common presenting symptom was jaundice (62.8%), anorexia, weight loss (39.8-54

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Paramyxoviruses and Multiple Sclerosis
...Show More Authors

Multiple Sclerosis (MS) is a progressive neurological disease characterized by periods of quiescence and exacerbation, epidemiological data suggest the notion that MS is an acquired autoimmune disease caused by environmental factors, probably infectious, in genetically susceptible individuals.The submitted research was attempted to study the possible viral (Paramyxoviruses) role in MS, the sera of 57 MS patients were assayed for anti-measles and anti-mumps IgG antibodies using ELISA technique, the results were compared in order to establish the presence or absence of a significant difference regarding both number of positive cases and antibodies titer between the two groups, the results revealed that there is no in number of measles posit

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Oct 01 2012
Journal Name
Al–bahith Al–a'alami
Internet and Press Blogging
...Show More Authors

The emergence of the Internet and its transformation in the early nineties of the last century led to a means of mass communication that brought about significant structural changes in the media map.

Over the course of historical development, the public did not engage the media in its behavior in the implementation and dissemination of an idea, generalization or theory put forward by media experts or practitioners through these means to do it. Blogs represent the most important service provided by the Internet in recent years which has gained special importance in the media field. Where the word “Blogs” has several names: (alternative media), (blogging press), (popular press) and other names.

The medi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jul 01 2022
Journal Name
Iop Conference Series: Earth And Environmental Science
Drought and Maize Breeding
...Show More Authors
Abstract<p>Tension caused by a lack of water (water stress or drought stress) represents the continuous and continuous threat to the survival of the plant, as many of the plants in which phenotypic or physiological modification takes place may not be able to continue and remain in the environment in which they live due to the water stress on it or the low soil moisture content. This of course is related to the prevailing weather conditions (lack of rain, high temperature, increased wind speed, low relative humidity in the atmosphere … etc.), so dry soil is defined as the shortage of soil water needed to the extent that its readiness for the plant decreases (that is, the threshold at which the </p> ... Show More
View Publication
Scopus (2)
Scopus Crossref
Publication Date
Tue Jun 01 2010
Journal Name
Journal Of The College Of Languages (jcl)
Racism and blacks struggle
...Show More Authors

    Traditionally, women playwrights in general, and black women playwrights in particular have been excluded from the American theater       because of racial and gender oppression. However, early twentieth-century African-American women playwrights, such as Angelina Weld Grimke (1880-1958), Alice Dunbar-Nelson (1875-1935), Marry Burrill (1879-1946), and Myrtle Smith Livingston (1901-1973), whose works have been overshadowed for decades, were able to express their awareness of the racial discrimination facing African-Americans. They also paved the way for the next generation of black women playwrights, such as Alice Childress (1920-1994), Lorraine Hansberry (1930-1965) and many others.

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 01 2020
Journal Name
Journal Of Planner And Development
Senses and urban Landscape
...Show More Authors

The city is often discussed in barren, eviscerated terms and in technical jargon by urban professionals as if it were a lifeless, detached being. In fact, it is a sensory, emotional, lived experience. How often do strategic urban plans start with the words ‘beauty’, ‘love’, ‘happiness’ or ‘excitement’, as opposed to ‘bypass’, ‘spatial outcome’ or ‘planning framework, So the research problem was formed by the weakness of the sensory perception of cities and the weakness of the sense of different spaces, which in turn leads to weakness of belonging, identity and clarity, Therefor we focus here on the sensory perception. The hypothesis Recognize Senses as helpful tool in increasing people's understanding of differe

... Show More
View Publication
Publication Date
Sun Dec 22 2024
Journal Name
Journal Of Baghdad College Of Dentistry
Photodynamic Therapy and Periodontology
...Show More Authors

This review highlights the importance of photodynamic therapy in periodontology. It can be confirmed that the photodynamic therapy as adjunct to classical scaling and root planing can be recommended as treatment option, which can by no means replace the classical therapy concepts. But even over an observation period of six months a slightly higher improvement of the clinical parameters was achieved than with SRP alone.

View Publication Preview PDF
Crossref (3)
Crossref