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.
Abstract
The goal of the research is to diagnose some of the negative phenomena which was discovered through the period from (2010 to 2014) as determined by the national strategy to eliminate the corruption which was set out by the joint council of the corruption elimination in Iraq. And to measure the gap in applying the legal rules by the administration, concerning the misconducts and felonies upon the state employments made by the state employee and how far they are applied in the studied sample and to show the nature of the rules and their importance and their role when they are applied in scientific and expertise manner. And to encourage the offices of the general supervisors to adhere to them which will lead t
... Show MoreThis research aims to identify the impact of Daniel's model on the development of critical thinking. In order to achieve this objective, the following hypotheses are formulated: 1. There is no statistically significant difference at the significance level (0.05) between the average differences in the posttest scores of the experimental group taught according to Daniel's model and the control group taught according to the traditional method in the measure of critical thinking. 2. There is no statistically significant difference at the significance level (0.05) between the average differences in the preand post-tests scores of the experimental group taught according to Daniel's model in the measure of critical thinking. The current research i
... Show MoreThe current research aims to assess the Brief Book of the Modern and Contemporary History of Asia from the perspective of the students in the Department of History, University of Baghdad. The study is carried out in Iraq and the research group has included students of the Department of History in the College of Education--Ibn Rushd and the College of Education for Women- University of Baghdad. The chosen sample of the assigned research consisted of (72) students from third stage in the Department of History, which equals (0.38%) of the total group members amounted (188) female and male students representing (40) students from the College of Education--Ibn Rushd, and 32 students from
... Show MoreThis experiment examined the effects of adding sodium alginate and KOJIC acid as substitutes of Conventional antibiotics to soybean lecithin extender on the characteristics of cryopreserved and frozen buffalo bull semen, as well as evaluation of their additions as antibiotics that to help lowering the microbial load. Following the collection and dilution of in the soybean lecithin extender, the experimental treatments were separated into five groups, as follows: T1: (control-) without adding any antibiotics; T2: (control+) adding the conventional antibiotics Gentamicin 0.4 IU and Tylosin 0.08 IU per 100 ml; T3: adding Kojic acid at (0.06 g/L) T4: adding sodium alginate at (0.6 mg/mL)T
L-arabinose isomerase from Escherichia coli O157:H7 Was immobilized with activated Bentonite from local markets of Baghdad, Iraq by 10% 3-APTES and treated with 10% aqueous glutaraldehyde, the results refer that the yield of immobilization was 89%, and pH profile of free and immobilized L-arabinose isomerase was 7 and 7.5 and it is stable at 6-8 for 60 min respectively, while, the optimum temperature was 30 and 35°C and it was stable at 35 and 40°C for 60 min but it loses more than 60 and 30% from its original activity at 50°C for free and immobilized L-arabinose isomerase respectively. Immobilized enzyme retained its full activity for 32 day, but it retained 73.58% of its original activity after storage for 60 d
... Show MoreIn this work, the effect of variation of semi-angle of the conical part on the vibration characteristics of cylindrical-conical coupled structure is investigated. The shell is made of polyester resin reinforced by continuous E-glass fibers. The case is analyzed experimentally and numerically for orthotropic shell structures. The experimental program is conducted by exciting the fabricated structure by an impact hammer and monitoring the response using an attached accelerometer for different semi-angles of the conical part.
Software named SIGVIEW is used to perform the signal processing on the acquired signal in order to measure the natural frequencies and the corresponding mode shapes. The numerical investigation is achieved using ANS
The present study included the microscopic and molecular identification of Entamoeba histolytica by using specific primers to detect four virulence factors possessed by Entamoeba histolytica. Virulence factors included Active Cysteine proteinase, Galactose/N-acetyl-D-galactose-lectin, Amoeba pore C and Phospholipase. Titanium dioxide nanoparticles (TiO2NPs) were synthesized from Pseudomonas aeruginosa which producing Pyocyanin pigment as a reducing agent to form it. After that we studied the ability ofTiO2NPs to inhibit virulence factors production and curing the genes responsible for encoding them by using four different dose 2 ,3, 4, 6 mg/Kg and administered by intraperitoneal injection
... Show MoreThis study was conducted at the field of poultry-Abu Gharib/department of Animal Production/college of agricultural engineering Sciences-university of Baghdad, during the period from 12/10/2019 to 24/11/2019 duration (42 days), to demonstrate the effect of adding different levels of Allicin to broiler diet on Glutathione level in blood and histological of thymus gland, total of 225 Ross 308 chicks was used. Birds were randomly distributed into five treatment groups which were: First treatment T1: without additives to diet (control), other treatments T2, T3, T4, T5 was added Allicin at a rate of (800,600,400,200 mg/Kg diet) respectively, and Allicin was added from first day until the end of the experiment for all addition treatments, results
... Show MoreThe researcher seeks to get scientific facts through knowing the relationship between the priorities of Yemeni audience in follow-up paper daily newspapers compared to surfing publics the online journalism sites and the nature of information obtained from online journalism sites and printed paper newspapers and the impact of the daily newspapers in the priority of issues and political events among a sample of a group of Yemeni readers in order to identify the extent to keep up the paper daily newspapers of the development in the field of online journalism and the extent of reading paper newspapers under the intense competition by online journalism sites, and are paper newspapers able to keep pace with the actual developments provided by
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