A field programmable gate array based modular motion control platform

The expectations from motion control systems have been rising day by day. As the systems become more complex, conventional motion control systems can not achieve to meet all the specifications with optimized results. This creates the necessity of fundamental changes in the infrastructure of the system. Field programmable gate array (FPGA) technology enables the reconfiguration of the digital hardware, thus dissolving the necessity of infrastructural changes for minor manipulations in the hardware even if the system is deployed. An FPGA based hardware system shrinks the size of the hardware hence the cost. FPGAs also provide better power ratings for the systems as well as a more reliable system with improved performance. As a trade off, the development is rather more difficult than software based systems, which also affects the research and development time of the overall system. In this paper a level of abstraction is introduced in order to diminish the requirement of advanced hardware description language (HDL) knowledge for implementing motion control systems thoroughly on an FPGA. The intellectual property library consists of synthesizable hardware modules specifically implemented for motion control purposes. Other parts of a motion control system, like user interface and trajectory generation, are implemented as software functions in order to protect the modularity of the system. There are also several external hardware designs for interfacing and driving various types of actuators

Precise torque control for interior mounted permanent magnet synchronous motors with recursive least squares algorithm based parameter estimations

Interior mounted permanent magnet (IPM) machines have superior features comparing to their counterparts for electric vehicle traction applications. Having relatively higher efficiency, high torque and power densities, low torque ripple and not requirement of regular maintenance are among their superior features. It is widely known that the precise torque control in practical IPM drives highly relies on accurate knowledge of machine parameters viz, inductance values and magnetic flux linkage. These machine parameters vary significantly in real time operation depending on manufacturing tolerance, operating temperature, inductance saturation, load torque and so on. It is known that d-and q-axis inductances and magnetic flux linkage at the full load operation may be approximately 20%, 35% and 20%, respectively, lower than their actual values at no-load operation. It is also commonly known in the literature for traction applications that these variations (considering wide range operation) have much influence on both drive system efficiency and output torque production compared to other system nonlinearities such as stator resistance variation. It has been achieved in this paper that these parameters are estimated online with fairly high accuracies of each, utilizing recursive least squares (RLS) algorithm. The superiority of the proposed drive achieving considerably higher output torque (-28,7% of peak torque) is validated through extensive realistic simulations with nonlinear machine model of a 4.1 kW prototype IPM machine designed and manufactured for traction applications. Proposed strategy and its superiority among state-of-art drives are discussed in detail. (c) 2021 Karabuk University. Publishing services by Elsevier B.V

Comparison of Interior Mounted Permanent Magnet Synchronous Motor Drives with Sinusoidal, Third Harmonic Injection, and Space Vector Pulse Width Modulation Strategies with particular attention to Current Distortions and Torque Ripples

Interior Mounted Permanent Magnet Synchronous Motors (IPMs) have become popular in electric vehicle traction applications in recent years due to their superior features such as high efficiency and high power density compared to other machines. Therefore, development of IPM drive systems is an important research area. In this study, three different pulse width modulation (PWM) strategies commonly used in machine drives are compared extensively in IPM drives. Simulations have been carried out with optimum dq-axes currents based on demanded torque from the system, and hence, the simulated drives are efficiency-optimized. Sinusoidal pulse width modulation (SPWM), third harmonic injection pulse width modulation (THIPWM), and space vector pulse width modulation (SVPWM) strategies have been employed in the drives, and comparisons have been made by paying particular attention to the total harmonic distortion (THD) rates of phase currents and torque ripples. It has been validated through extensive simulations that the SVPWM strategy has less THD percentage for IPM drives than SPWM and THIPWM at wide operating points, and hence, the current and torque responses are better with smooth output torque. Simulation results also validate that the current distortions and torque ripples are the highest when SPWM strategy is adopted in the drives, and hence, the THIPWM strategy is superior to the SPWM. © 2023 Istanbul University. All rights reserved

A field programmable gate array based motion control platform

The expectations from motion control systems have been rising day by day. As the system becomes more complex, conventional motion control systems can not achieve to meet all the specifications with optimized results. This creates the need of re-designing the control platform in order to meet the new specifications. Field programmable gate arrays (FPGA) offer reconfigurable hardware, which would result in overcoming this re-designing issue. The hardware structure of the system can be reconfigured, even though the hardware is deployed. As the functionality is provided by the hardware, the performance is enhanced. The dedicated hardware also improves the power consumption. The board size also shrinks, as the discrete components can be implemented in FPGA. The shrinkage of the board size also lowers the cost. As a trade-off, FPGA programming is more complicated than software programming. The aim of this thesis is to create a level of abstraction in order to diminish the requirement of advanced hardware description language knowledge for implementing motion control algorithms on FPGA's. The hardware library is introduced which is specifically implemented for motion control purposes. In order to have a thorough motion control platform, other parts of the system like, user interface, kinematics calculations and trajectory generation, have been implemented as a software library. The control algorithms are tested, and the system is verified by experimenting on a parallel mechanism

Single step therapy for abscess foci localized at different parts of the body using trocar type catheter: Results of two year-experience

Objectives: The aim of this study was to emphasize the feasibility and cost effectiveness of trocar type catheter in percutaneous abscess drainage under imaging guidance and to determine the clinical efficacy of the method.Materials and methods: From June 2008 to December 2010, 48 patients who were referred to interventional radiology unit, in order to undergo percutaneous abscess drainage. All was data including age, the organ or the part of the body where the abscess was localized and size of abscess were recorded. Forty-two (87%) patients underwent drainage with ultrasonographic guidance, while 6 (13%) underwent with computed tomography guidance. One pediatric patient underwent systemic sedation anesthesia (with remiphentanyl and midazolam) and the rest of the patient with local anesthesia (with prilocain hydrochlorid). Catheterization procedure with which abscess drainage was done accepted as technically successful.Results: Imaging guided percutaneous abscess drainage procedures were performed with trocar type catheter to localized abscesses in different organs or systems in 48 patients (25 men, 23 women, mean age 52 years, range 2-82 years). Technical success was 100% in all cases. No patient had a complication during the procedure. Time to extraction of percutaneous catheter after drainage procedure was 5-28 days (mean 11.2 days). There was no recurrence except for a case, in which an abscess at the splenectomy site was successfully drained.Conclusion: Percutaneous drainage with imaging guidance using the trocar type catheter should be preferred because of its feasibility, cost-effectiveness, and reduced rate of complications in treating abscesses, which localized at different organ systems

Examining to see elite sight-disabled athletes according to the dimensions of the scale of motivation in sport

Made the purpose of this study is to examine to see disabled athletes according to the dimensions of the scale of motivation in sport. The study group is comprised of 168 visually impaired athletes in total, including 51 females and 117 males, identified by the targeted sampling method, between the ages of 15-25, who do sports at elite level. The Sport Motivation Scale (SMS) was developed by Pelletier (1995) basing on the Theory of Self Determination by Deci and Ryan (1985). The purpose of SMS is to determine the level of "internal motivation, external motivation and nonmotivation” of the person in the sports environment and to identify the source of motivation of the person (Kazak, 2004). Validity and reliability of the scale for Turkish athletes was studied by Kazak (2004).  In conclusion, this study has demonstrated that to know and succeed and to experience stimuli and identification subdimensions are effective in sports attendance of visually impaired athletes engaged in sports at elite level. Moreover, it has been demonstrated that age, education level and sports branch variables have an impact on tendency for sports. It can be concluded that compared to older athletes, younger athletes have low tendency for sports because of anxiety and embarrassment and are not conscious about why they do sports. It has been concluded that athletes of weight lifting and judo, which have contribution to physical development at the top level, believe the nature of their sports branch contributes more to their physical development and their strength is acknowledged and appreciated by other people.// Annotate Highligh

Clinical value of pre-operative polyvinyl alcohol embolization in juvenile nasopharyngeal angiofibroma

Jüvenil nazofarengeal anjiofibromun tedavisinde pre-operatif embolizasyonun yeri tartışmalıdır. Embolizasyonun klinik etkinliğini değerlendirmek amacıyla, kliniğimizde 1994-2000 yılları arasında histopatolojik tanısı Jüvenil nazofarengeal anjiofibrom gelen, embolizasyon uygulanan ve uygulanmayan on hasta retrospektif olarak analiz edilmiştir. Bu vakaların beşine polivinil alkol ile selektif embolizasyon uygulanmıştır. Sadece cerrahi tedavi uygulanan olgulardaki intra-operatif kanama miktarı ortalama 2530 cc, verilen transfüzyon ünitesi ortalama 4.4 unit olarak bulunmuştur. Cerrahi öncesi pre-operatif embolizasyon uygulanan olgularda ise intra-operatif kanama miktarı ortalama 1590 cc, verilen transfüzyon ünitesi ise ortalama 2 unittir. Sonuçlar, pre-operatif polivinil alkol ile embolizasyonun intra-operatif kanama miktarını, transfüzyon ihtiyacını ve operasyon süresini azaltmada güvenilir ve etkili bir yöntem olduğunu göstermiştir.Role of the pre-operative embolization in the treatment of Juvenile nasopharyngeal angiofibroma, is controversial. For the purpose of evaluating clinical effectiveness of embolization, ten patients who came to our clinic with histopathological diagnosis of Juvenile nasopharyngeal angiofibroma and who are and not administered embolization between 1994 and 2000, have been retrospectively analyzed. in five of the cases, selective embolization method has been administered with polyvinyl alcohol (PVA). in cases where only surgical treatment is administered, it is found that average intraoperative bleeding amount is 2530 cc and transfusion unit administered is 4.4 units, in the cases where preoperative embolization is administered, intraoperative bleeding amount is 1590 cc and number of transfusion units is 2. Results indicated that embolization with preoperative polyvinyl alcohol is a reliable and effective method in decreasing the amount of intraoperative bleeding, transfusion need and duration of the surgical operation

Protective effects of pomiferin isolated from Maclura pomifera on ischemia-reperfusion injury of rat ovary: biochemical and histopathologic evaluation

Background: The aim of this study was to investigate the antioxidant and anti-inflammatory properties of pomiferin, a prenylated flavonoid was purified from Maclura pomifera by thin layer chromatography method, on oxidative stress, sterile inflamation and ovarian tissue damage caused by ischemia-reperfusion model. Methods: Thirty female Wistar albino rats were divided into five groups. In the group CN only laparotomy operation was performed. In group CNPomiferin, rats received 200 mg/kg pomiferin. In group IRVehicle, reperfusion for 3 h performed after an ischemic period of 3 hours. In groups IRPomiferin100 and IRPomiferin200 rats received 100 mg/kg and 200 mg/kg doses of pomiferin, by oral gavage 1 houes before reperfusion. After the experiments, tissue level of malondialdehyde (MDA) and activities of myeloperoxidase (MPO), catalase (CAT), superoxide dismutase (SOD) were determined, and histopathological changes were examined in all rat ovarian tissue. Results: It was determined that irreversible cell damage such as apoptotic and necrotic deaths and reversible cell damage occurred in follicular, endothelial and stromal cells due to oxidative stress in the group IRVehicle. In this group, it was determined that the LPO level exceeded the cellular antioxidant capacity (SOD and CAT enzyme activities) and the PMNL infiltration and activity (MPO), an indicator of sterile inflammation, increased. It was determined that oxidative stress sterile inflammation and irreversible cell damage decreased in a dose-dependent manner with pomiferin treatment. Conclusions: Pomipherin treatment strongly protects ovarian follicles and vascular structures against ischemia-reperfusion injury, thus it may prevent the reduction of ovarian follicle reserve, which is an indicator of female fertility

Application of first-pass contrast bolus tracking sequence for the assessment of morphology and flow dynamics in cardiac MRI

PURPOSEThere are two well-known indications for first-pass perfusion in the literature. First is the evaluation of myocardial ischemia, and the other is the evaluation of tumor vascularity. Our aim was to assess the value of a first-pass contrast bolus tracking sequence (FPCBTS) for cases unrelated to these pathologies. MATERIALS AND METHODSA total of 35 patients (age range, 1 day to 66 years; mean age, 10.4±19.2 years; median age, 4.5 months) with suspected congenital (n=31) and acquired (n=4) heart and great vessel disease were included in the study. All the patients underwent cardiac magnetic resonance imaging (MRI) and FPCBTS, and 20 patients underwent contrast enhanced magnetic resonance angiography (CE-MRA). We used cardiac MRI and CEMRA for anatomic evaluation and FPCBTS for dynamic flow evaluation. RESULTSTruncus arteriosus, double outlet right ventricle, tetralogy of Fallot, corrected transposition of great arteries, atrial and ventricular septal defect, aortic rupture, cardiac hydatid cyst, tricuspid atresia, anomalous pulmonary venous return, and interrupted aorta were detected using the technique described here. Septal defects in six patients and atrial aneurysm in two patients were excluded. The shunt gap and flow direction of the septal defects, a ruptured wall in a dissected aorta, a hydatid cyst, and the atrial relationship in two cases with paracardiac masses were diagnosed easily using this dynamic evaluation technique. CONCLUSIONFPCBTS can be performed in addition to cardiac MRI and CEMRA to reveal flow dynamics and morphology

Incidence and Management of Delayed Epistaxis Following Endoscopic Skull Base Surgery

Objective:Among other complications of endoscopic skull base surgery, delayed epistaxis has not been given much importance. This report presents postoperative delayed nosebleed cases in a large number of patients who underwent an endoscopic endonasal transsphenoidal approach to the sellar region for resection of lesions.Methods:Three hundred and sixty three patients who were reached to the sellar region by endoscopic endonasal transsphenoidal route and operated was included in the study. Retrospective chart reviewing of these patients was performed. The correlation between the duration of nosebleeds, bleeding location, treatment methods and comorbidities of the patients were evaluated.Results:Ten patients (3.6%) reported delayed epistaxis in the postoperative period and were referred to the otolaryngology department. Postoperative epistaxis occurred between days 7th and 33th (mean 16.5) days. The treatment consisted of chemical silver nitrate cauterization in two patients, return to the operating room in three patients, nasal packing in five patients.Conclusion:Delayed postoperative epistaxis often has no obvious etiology, and intervention requires teamworking. Well-coordinated teamworking of the neurosurgeon with other specialities such as neuroradiology and otorhinolaryngology is needed to achieve better results