Adaptive human force scaling via admittance control for physical human-robot interaction

The goal of this article is to design an admittance controller for a robot to adaptively change its contribution to a collaborative manipulation task executed with a human partner to improve the task performance. This has been achieved by adaptive scaling of human force based on her/his movement intention while paying attention to the requirements of different task phases. In our approach, movement intentions of human are estimated from measured human force and velocity of manipulated object, and converted to a quantitative value using a fuzzy logic scheme. This value is then utilized as a variable gain in an admittance controller to adaptively adjust the contribution of robot to the task without changing the admittance time constant. We demonstrate the benefits of the proposed approach by a pHRI experiment utilizing Fitts’ reaching movement task. The results of the experiment show that there is a) an optimum admittance time constant maximizing the human force amplification and b) a desirable admittance gain profile which leads to a more effective co-manipulation in terms of overall task performance.WOS:000731146900006Scopus - Affiliation ID: 60105072Q2ArticleUluslararası işbirliği ile yapılan - EVETOctober2021YÖK - 2021-22Eki

Resolving conflicts during human-robot co-manipulation

UK Research and Innovation, UKRI: EP/S033718/2, EP/T022493/1, EP/V00784XThis work is partially funded by UKRI and CHIST-ERA (HEAP: EP/S033718/2; Horizon: EP/T022493/1; TAS Hub: EP/V00784X).This paper proposes a machine learning (ML) approach to detect and resolve motion conflicts that occur between a human and a proactive robot during the execution of a physically collaborative task. We train a random forest classifier to distinguish between harmonious and conflicting human-robot interaction behaviors during object co-manipulation. Kinesthetic information generated through the teamwork is used to describe the interactive quality of collaboration. As such, we demonstrate that features derived from haptic (force/torque) data are sufficient to classify if the human and the robot harmoniously manipulate the object or they face a conflict. A conflict resolution strategy is implemented to get the robotic partner to proactively contribute to the task via online trajectory planning whenever interactive motion patterns are harmonious, and to follow the human lead when a conflict is detected. An admittance controller regulates the physical interaction between the human and the robot during the task. This enables the robot to follow the human passively when there is a conflict. An artificial potential field is used to proactively control the robot motion when partners work in harmony. An experimental study is designed to create scenarios involving harmonious and conflicting interactions during collaborative manipulation of an object, and to create a dataset to train and test the random forest classifier. The results of the study show that ML can successfully detect conflicts and the proposed conflict resolution mechanism reduces human force and effort significantly compared to the case of a passive robot that always follows the human partner and a proactive robot that cannot resolve conflicts. © 2023 Copyright is held by the owner/author(s).2-s2.0-8515037875

3-Dimensional Nonlinear Finite Element Analysis of both Thermal and Mechanical Response of Friction Stir Welded 2024-T3 Aluminum Plates

This paper attempt to predict numerically both the temperature distribution during friction stir welding process of 2024-T3 aluminium plates and the resulting thermal residual stress by sequentially coupling the thermal histories into the mechanical model assuming elastic-perfectly plastic metal behaviour in accordance with the classical metal plasticity theory. The commercial code ANSYS 14 is used in Thermomechanical modelling of friction stir welding of aluminium 2024-T3.  Heat input from the tool shoulder and the tool pin are considered in the finite element analysis model. A moving heat source with a heat distribution simulating the heat generated from the friction between the tool shoulder and the work piece is used in the heat transfer analysis The longitudinal stress components are found to be the highest tensile stress components and correspond to the temperature profiles within the heat affected zone of the weld. The through-thickness (normal) stresses are found to be negligible compared with the longitudinal and transverse stress components. To facilitate simulation runs of the proposed model an APDL (ANSYS Parametric Design Language) code is developed to extract the thermal history and the subsequent thermal stresses. The effects of various heat transfer conditions at the bottom surface of the workpiece, thermal contact conductances at the work-piece and the backing plate interface on the thermal profile in the weld material are taken into considerations. The results of the simulation are compared to other published experimental results and the agreement was good. Keywords: Friction stir welding, Finite element, Three dimensional modeling, Thermal stresses

TECHNOLOGICAL ANALYSIS OF FLAT SURFACE CONDITIONS BY MAGNETIC ABRASIVE FINISHING METHOD (MAF)

This study introduced the effect of using magnetic abrasive finishing method (MAF) for finishing flat surfaces. The results of experiment allow considering the MAF method as a perspective for finishing flat surfaces, forming optimum physical mechanical properties of surfaces layer, removing the defective layers and decreasing the height of micro irregularities. Study the characteristics which permit judgment parameters of surface quality after MAF method then comparative with grinding

The Effect of Magnetic Abrasive Finishing on the Flat Surface for Ferromagnetic and non-Ferromagnetic materials

Magnetic Abrasive Finishing (MAF) is an advanced finishing method, which improves the quality of surfaces and performance of the products. The finishing technology for flat surfaces by MAF method is very economical in manufacturing fields an electromagnetic inductor was designed and manufactured for flat surface finishing formed in vertical milling machine. Magnetic abrasive powder was also produced under controlled condition. There are various parameters, such as the coil current, working gap, the volume of powder portion and feed rate, that are known to have a large impact on surface quality. This paper describes how Taguchi design of experiments is applied to find out important parameters influencing the surface quality generated during MAF method. In the experimental part, two types of materials from non-ferromagnetic and ferromagnetic (Aluminum alloy 7020 and stainless Steel 410 respectively) were considered with different parameters. Regressions models based on statistical-mathematical approach were obtained by using SPSS software for two materials

Effect of Pregnancy on Haematological and Biochemical Profiles in the Mountain Gazelles (Gazella gazelle)

Abstract: The propose of this study was to investigate the effect of pregnancy on hematological and biochemical parameters. This parameters were measured in 20 blood samples collected from 10 pregnant and 10 non-pregnant captive mountain gazelles (Gazella gazella) in Saudi Arabia. The effects of pregnancy on the intracellular concentrations of sodium (Na + ), Potassium (K + ), Blood Urea Nitrogen (BUN), Alanine amino Transferase (ALT), Aspartate amino Transferase (AST), Total protein, albumin, Alkaline Phosphatase (AP), Creatinine, Cholesterol and Triglyceride were analyzed. The levels of Sodium ions, GGT, ALT, AST, cholesterol and triglycerides were significantly (p<0.01) increased in pregnant group compared to non-pregnant group. These result due to the physiological and metabolism changes during pregnancy. So this study suggested to supply pregnant Gazelles with proteins during pregnancy

Patient Satisfaction and Its Predictors in the General Hospitals of Southwest Saudi Arabia: A Cross-sectional Survey

Background: Patient satisfaction occupies a central position in measuring the quality of care as it provides information on the provider's success, meeting the patient’s values and expectations. Hence, it is an essential tool for assessing health services outcomes. This study aimed to assess patients' satisfaction level and factors influencing healthcare quality of general hospitals in the Jazan region, Saudi Arabia (SA). Methods: This observational cross-sectional study was conducted on a sample of 423 patients selected through stratified random sampling from general hospitals of the Jazan region. Results: The overall satisfaction rate among the study participants was 80.9%. Satisfaction with food services was the highest (91.15%) followed by doctor services (81.0%), reception and entry procedures (80%), and nursing services (78.15%). The various aspects of satisfaction with doctors and nurses included the treatment prescribed by physicians, clarity in communication with patients, compassion and providing clear explanation of what they were doing. However, about 27.3% of the patients were dissatisfied with the length of waiting period before seeing a doctor. Binary logistic regression analysis suggested that uneducated patients and patients with secondary school education were more likely to have higher satisfaction level than university-educated patients (OR = 3.40, 95% C.I. [1.56–7.45], p = 0.002), (OR = 2.66, 95% C.I. [1.28–5.55], p = 0.009), and (OR = 2.29, 95% C.I. [1.40–3.73], p = 0.001), respectively. Conclusion: The health services satisfaction level was high in the Jazan population. However, some aspects of dissatisfaction were reported, such as the long waiting period before seeing a doctor. These aspects are recommended to be improved to ensure that the services provided by general hospitals are of high quality

Challenges Facing Healthcare Administration , Public Health, Nurses And Microbiology Team Towards Prevention Of Transmission Of Wild Poliovirus

The Global Commission for the Certification of the Eradication of Poliomyelitis will declare the world free of wild poliovirus transmission when no wild virus has been detected for a minimum of 3 consecutive years, and all laboratories that possess wild poliovirus materials have implemented effective containment measures. These achievements can be attained through the collaborative efforts of healthcare administration, public health, nursing, and microbiology teams in addressing the challenges associated with transmission. The primary obstacles to achieving polio eradication are the lack of robust political backing at the national level, insufficient financial support that hampers the implementation of WHO recommendations, potential issues with the availability of polio vaccine due to inadequate support, and the unsatisfactory rate of progress in polio surveillance

Risk and diagnostic factors and therapy outcome of neonatal early onset sepsis in ICU patients of Saudi Arabia: a systematic review and meta analysis

BackgroundNeonatal early onset sepsis (NEOS) is a serious and potentially life-threatening condition affecting newborns within the first few days of life. While the diagnosis of NEOS was based on clinical signs and symptoms in the past, recent years have seen growing interest in identifying specific diagnostic factors and optimizing therapy outcomes. This study aims to investigate the diagnostic and risk factors and therapy outcomes of neonatal EOS in ICU patients in Saudi Arabia, with the goal of improving the management of neonatal EOS in the country.MethodsThis method outlines the protocol development, search strategy, study selection, and data collection process for a systematic review on neonatal early onset sepsis in Saudi Arabian ICU patients, following the PRISMA 2020 guidelines. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is a well-established guideline that provides a framework for conducting systematic reviews and meta-analyses in a transparent and standardized manner. It aims to improve the quality and reporting of such research by ensuring clear and comprehensive reporting of study methods, results, and interpretations. The search strategy included electronic databases (PubMed, Embase, Google Scholar, Science Direct, and the Cochrane Library) and manual search of relevant studies, and data were extracted using a standardized form.ResultsThe systematic review included 21 studies on neonatal sepsis in Saudi Arabia, with varying study designs, sample sizes, and prevalence rates of sepsis. Group B streptococcus and E. coli were the most commonly isolated pathogens. Various diagnostic factors and risk factors were reported, including hematological parameters, biomarkers, and blood cultures. The quality of the included studies was assessed using the Newcastle-Ottawa Scale and Joanna Briggs Institute critical checklist.ConclusionsThe review identified a number of risk and diagnostic factors and therapy outcomes for neonatal sepsis. However, most of the studies were having small scale cohort groups. Further research with controlled study designs is needed to develop effective prevention and management strategies for neonatal sepsis in Saudi Arabia

It is time to define an organizational model for the prevention and management of infections along the surgical pathway : a worldwide cross-sectional survey

Background The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. Methods A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. Results Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. Conclusion Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened.Peer reviewe