research centers


Search results: Found 84

Listing 1 - 10 of 84 << page
of 9
>>
Sort by

Article
Sliding Mode Controller Design for a Crane Container System

Loading...
Loading...
Abstract

Abstract- Applying automatic control on gantry cranes to move loads with minimal sway angle is considered as a challenge due to the crane system uncertain parameters and a robust automatic control is needed. In this paper a sliding mode controller is applied to overcome the crane system uncertainties and achieve the desired performance. Some labor is spent to transform the system to the regular form and an error function is written depending on the transformed variables then a switching function in terms of the error function is constructed and a sliding mode controller is designed to make the error function reach zero so the crane moves to the specified displacement with minimum sway angle. Stability analyses are provided to show that the system is stable under the control we proposed. Simulations are held by software to validate the effectiveness of our work and prove that the proposed control is successful in giving our system the preferred behavior then Results are discussed and some point view is to be put.


Article
Combined Sliding Mode Control with a Feedback Linearization for Speed Control of Induction Motor

Loading...
Loading...
Abstract

Induction Motor (IM) speed control is an area ofresearch that has been in prominence for some time now. In thispaper, a nonlinear controller is presented for IM drives. Thenonlinear controller is designed based on input-output feedbacklinearization control technique, combined with sliding modecontrol (SMC) to obtain a robust, fast and precise control of IMspeed. The input-output feedback linearization controldecouples the flux control from the speed control and makes thesynthesis of linear controllers possible. To validate theperformances of the proposed control scheme, we provided aseries of simulation results and a comparative study between theperformances of the proposed control strategy and those of thefeedback linearization control (FLC) schemes. Simulationresults show that the proposed control strategy scheme showsbetter performance than the FLC strategy in the face of systemparameters variation


Article
Experimental prototype for PWM – Based Sliding Mode Boost Converter

Authors: R. A. Abdulhalem --- Haroutuon A. Hairik --- Asmaa J. Kadhem
Journal: Iraqi Journal for Electrical And Electronic Engineering المجلة العراقية للهندسة الكهربائية والالكترونية ISSN: 18145892 Year: 2011 Volume: 7 Issue: 1 Pages: 35-41
Publisher: Basrah University جامعة البصرة

Loading...
Loading...
Abstract

The paper dells with a modified experimentalprototype for pulse-width modulation (PWM) sliding modecontrol (SMC) applied to a DC-to-DC-boost converter operatedin continuous conduction mode (CCM). Experimental resultsshow that the proposed control schme provides good voltageregulation and is suitable for common DC-to-DC conversionpurposes. The prototype and its implementation are given indetail. The static and dynamic performances of the The staticand dynamic performances of the experimental system arerecorded. Experimental results show that the proposed controlscheme provides good voltage regulation and is suitable forcommon DC-to-DC conversion purposes.


Article
Comparison Between Laceback and Tie-back in Sliding Mechanics (An in vitro study)

Author: Khawla M Awni
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2012 Volume: 12 Issue: 23 Pages: 148-152
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

ABSTRACTAims: The current study aims to investigate the rate of space closure, tipping and rotation of canine during its retraction by laceback and tieback using standard ceramic brackets along 2 types of arch-wires using typodont simulation system (Ormco). Materials and Methods: The standardization crite-ria were all typodont teeth situated in well aligned position, covered and immobilized by the acrylic bite except canine, laceback and tieback were used to slide the canine. Results: The present study showed that when slide the canine on 0.017x 0.025 inch archwire gave rise to significant decrease in the rate of space closure, degree of tipping and rotation as compared when sliding it on 0.020 inch archwire, also sliding the canine using laceback as a method of retraction gave rise to a significant decrease in the rate of space closure, degree of tipping and rotation as compared with tieback. Conclusions: It was concluded that canine retraction using laceback retraction method along 0.017x0.025 inch archwire gave rise to a significant decrease in the rate of space closure, degree of tipping and rotation.


Article
Effect of Heat Treatments on Sliding Wear Behavior of Medium Carbon Steel
تاثير المعاملات الحرارية على سلوك البلى الانزلاقي لفولاذ متوسط الكاربون

Author: Ahlam Abdalamir Mohamed احلام عبدالامير محمد علي
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2012 Volume: 30 Issue: 13 Pages: 318-328
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The aim of this work is to study the effect of heat treatments on the wear rate ofthe medium carbon steel which included normalizing and different quenchingmedia (air, oil, salt solution at concentration %25). Quenching Include heating toa temperature of 870Co and then rapid cooling. A Pin -on-Disc technique was usedto measure the wear rate under dry sliding conditions with applied and differentsliding times with constant sliding speed of disc (641 r.p.m) and hardness of thesteel disc (48 HRC).The results show that the wear rate increases with applied loads, and withincreasing sliding time for all heat treated specimens it was found that the hardnessvalues of the quench specimens at salt solution is higher than that of normalizedspecimens and quenched specimens in the oil.

تضمن هذا البحث دراسة تاثير المعاملات الحرارية على معدل البلى الانزلاقي لفولاذمتوسط الكاربون وهي المعادلة والتقسية باوساط تقسية مختلفة (الزيت، محلول ملحيبتركيز 25 %). وتضمنت التقسية التسخين عند درجة حرارة ( 870 ) م° ثم التبريد السريع لكللقياس معدل البلى (Pin – on Disc) العينات المقساة ، وقد استخدمت تقنية المسمار على القرصتحت ظروف الانزلاق الجاف وعند تسليط احمال مختلفة وتثبيت زمن الانزلاق ، وفترات انزلاقHRC ) مختلفة مع تثبيت سرعة الدورانية للقرص( 641 ) دورة/دقيقة وصلادة القرص الفولاذي48 ). وقد اظهرت النتائج ان معدل البلى يزداد بزيادة الحمل المسلط والفترة الزمنية للانزلاقلجميع العينات المعاملة حراريا واظهرت النتائج ان قيم الصلادة للعينات المقساة بالمحلول الملحياعلى من العينات المقساة بالزيت والعينات المعاملة بالمعادلة.


Article
Evaluation of space closure rate, tipping and rotation of canine during it's retraction with sliding mechanics(An In vitro study(.

Authors: Hussain A Obaidi --- Yonis M Saeed
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2006 Volume: 6 Issue: SpIss Pages: S64-S70
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

To evaluate of the effects of using different methods of elastic chain attachment, different shapes of base arch wire (round and rectangular) and different ligation techniques on the rate of space closure, degree of tipping and degree of rotation of canine during translatory displacement of canine's bracket via wire using Typodont simulation system. Materials and Methods: Typodont teeth situated in well– aligned position, The criteria of the subject are covered and immobilized by the acrylic bite except canine; Elastic chain exerting 180gm of force on canine measured carefully by Tension Gauge; The available space was (14 mm) measured by digital vernia; The angle between bite plane extension bar and canine extension bar were (90) measured by protractor directly on a photograghs that were taken for Typodont using digital camera from both vertical and horizontal direction. The data were subjected to the statistical analysis at P≤ 0.05 significant level. Results: Canine sliding over rectangular arch wire gave rise to significant decrease in degree of tipping and rotation with significant reduction in rate of space closure, Second, stainless steel ligature and elastomeric ties of conventional ligation technique gave rise to a significant decrease in the degree of tipping and rotation with significant reduction in rate of space closure, elastic chain onto hook of canine bracket, gave rise to significant decrease of tipping and rotational degree with significant increase in rate of space closure. Conclusions: the methods in which elastic chain is attached to canine's hook using rectangular wire with elastomeric ties and the elastic chain is attached to canine's hook using rectangular wire with stainless steel ligature are favorable affecting canine sliding, where both were produced significantly the lowest degree of tipping and rotation with satisfactory rate of space closure.


Article
Evaluation of the effect of different points of orthodontic force application ( A typodont study)

Authors: Ahmed Gh Mohammed --- Ahmed A Abdul– Mawjood --- Omar KhM Thiab
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2011 Volume: 11 Issue: SpIss Pages: S178-S138
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: To determine the effect of different points of force application on dimensional positions and the ratio of space closure of maxillary canine using sliding mechanics. Mater– ials and Methods: The study included eight groups which were categorized according to the differences in the points from which the retraction force was applied. A 180 gm was applied by short elastic chain to retract the right maxillary canine on 0.0180.025'' rectangular stainless steel (SS) wire and along 13mm available space. In both vertical and horizontal direction, photographs were taken by digital camera and the angle between canine extension bar and bite plane extension bar was measured by protractor to determine tipping and rotation whereas rate of space closure was measured by digital vernia. Results: The results showed that the maximum rate of space closure was achieved when elastic chain was attached between molar hook to canine hook and the minimum degree of tipping was achieved when elastic chain attached between premolar bracket to canine hook while minimum rotation occurred when the attachment was between premolar hook to canine hook. Conclusions: Changing the distance between the points of force application significantly affects the rate of space closure, tipping and rotation. The use of hook significantly increases the rate of space closure and decreases tipping and rotation

Keywords

Sliding --- tipping --- rotation


Article
Sliding Mode Controller for Nonlinear System Based on Genetic Algorithm
مسيطرات النمط الأنزلاقي للأنظمة اللا خطية بالأعتماد على الخوارزمية الجينية

Author: Ahmed Khalaf Hamoudi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2014 Volume: 32 Issue: 11 Part (A) Engineering Pages: 2745-2759
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Sliding Mode Controller (SMC) is a simple and effective method to recognize a robust controller for nonlinear system. It is a strong mathematical tool which gives a nonlinear robust controller with acceptable performance. The chattering phenomenon is the major drawback that sliding mode control suffers from. This phenomenon causes a zigzag motion along the sliding surface. In this work to design SMC, the Saturation function (i.e., boundary layer) has been used instead of the Sign function that was used in classical sliding mode controller in order to reduce the chattering phenomena which are appearing in the sliding mode phase. The genetic algorithms have also been proposed in this work for the parameter selection method of Sliding Mode Controller and the results showed a high speed of the system state for reaching the sliding surface during the reaching phase and a chattering reduction during the sliding phase. A pendulum system has been used for testing the designed sliding mode controller. The simulation results showed good validity of the suggested method. Matlab programming and simulink were adopted for the simulation results.

تعتبر طريقة أستخدام مسيطرات النمط الأنزلاقي بسيطة وفعالة للحصول على مسيطر متين وجيد للتعامل مع الأنظمة اللاخطية, وهي طريقة رياضية فعالة تعطي مسيطر متين لا خطي يعطي نتائج ذات خصائص ومواصفات جيدة ومقبولة. وتعتبر ظاهرة التذبذب هي أكثر صفة سيئة تعاني منها أنظمة النمط الأنزلاقي. وتسبب هذه الظاهرة حركة متعرجة على أمتداد السطح الأنزلاقي. في هذا البحث وعند تصميم مسيطرات النمط الأنزلاقي تم أستخدام دالة الأشباع بدلا من دالة الأشارة المستخدمة في أنظمة السيطرة الأنزلاقية التقليدية من أجل تقليل ظاهرة التذبذب التي تظهر في مرحلة الأنزلاق. كذلك تم أقتراح الخوارزمية الجينية في هذا البحث من أجل أختيار العناصر المكونة لمسيطر النمط الأنزلاقي و أظهرت النتائج سرعة عالية لحالة النظام للوصول الى السطح الأنزلاقي خلال مرحلة الوصول وكذلك تقليل في ظاهرة التذبذب في مرحلة الأنزلاق. تم أستخدام نظام البندول لأختبار مسيطر النمط الأنزلاقي الذي تم تصميمه. أن التنفيذ من خلال المحاكاة بالحاسوب أظهر نتائج جيدة وأيجابية للطريقة المقترحة في هذا البحث. لقد تم أستخدام البرمجة بلغة ماتلاب لأيجاد نتائج المحاكاة بأستخدام بالحاسوب.


Article
Design of Integral Sliding Mode Controller for Servo DC Motor

Authors: Bashar Fateh Midhat --- Amjad Jaleel Humaidi --- Firas A. Raheem
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 3 Pages: 685-691
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

DC servo motor is simple in construction and control and has many applications. However, the uncertainties due to its parameters changes such as load torque and friction are an evitable. Therefore, a robust controller has to be employed for keeping specified requirements irrespective to parameter variations. In the present work, two sliding mode controllers have been suggested to control the speed of DC motor under motor load changes; classical and integral sliding mode controllers. The integral slide mode control could show better tracking characteristics than its counterpart and also could compensate the change in system parameters.

يتميز المحرك المؤازر يسهولة التركيب والسيطرة وله تطبيقات عديدة. مع ذلك، فان هناك حتمية في ظهور او وجود ((Uncertainties بسبب تغير معلماته. لذلك يتوجب استخدام مسيطر متين للحفاظ على المتتطلبات المحددة والموصوفة للمنظومة بغض النظر عن تغير تلك المعلمات. في هذا البحث تم اقتراح مسيطرين ذات النمط الانزلاقي لغرض السيطرة على سرعة المحرك ذو التيار المستمر تحت تاثير احمال مختلفة وهما: المسيطر التقليدي ذات النمط الانزلاقي وكذلك المسيطر التكاملي ذات النمط الانزلاقي. اظهرت النتائج بان المسيطر التماملي ذات النمط الانزلاقي اعطى اداء اعلى وخصائص متابعة افضل من المسيطر التقليدي وتمكن من اجراء التعويض الناتج من تغير الحاصل في متغيرات المنظمومة بشكل افضل من نظيره.


Article
Backstepping Nonlinear Control for Blood Glucose Based on Sliding Mode Meal Observer
مسيطر لاخطي تراجعي خطوة بخطوة للسيطرة على الكلوكوز في الدم بالاعتماد على المخمن المنزلق لتخمين الوجبة

Authors: Shibly Ahmed AL-Samarraie شبلي احمد السامرائي --- Sazan Dawood Salman سازان داود سلمان
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2018 Volume: 21 Issue: 3 Pages: 436-444
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

Diabetes is one of the most critical diseases in the world which requires measuring the concentration of glucose also the injection of insulin to control the glucose rate in the body. The proposed controller is applied to the Bergman’s three-state minimal patient model, where the model is considered certain but with unknown meal. In the present work, a nonlinear controller is designed to control the concentration of glucose based on the Backstepping approached with a sliding mode for observing the disturbance meal. So will have estimated the meal and have canceled the effect that the glucose concentration has regulating to the basal level.The effectiveness of the proposed controller, which represent the insulin dose, is proved via simulating the Bergman’s model with designed controller via MATLAB Simulink software. The result clarify the ability and the robustness of the proposed controller.

يعد مرض السكري من أكثر الأمراض خطورة في العالم والذي يتطلب قياس تركيز الكلوكوز وأيضاً حقن الأنسولين للتحكم في معدل الكلوكوز في الجسم. يتم تطبيق مسيطر مقترح للتحكم بنموذج المريض الحد الأدنى الخاص بموديل ببركمان بثلاث حالات ، حيث يعتبر النموذج مؤكد مع وجبة غير معروفة. في العمل الحالي ، تم تصميم وحدة تحكم غير خطية للتحكم في تركيز الجلوكوز أساسا هو مسيطر تراجعي خطوة بخطوة مع المخمن المنزلق لتخمين الاضطراب (الوجبة). لذلك بعد أن يتم تقدير الوجبة ، يتم إلغاء التأثير ويتم تنظيم تركيز الكلوكوز على مستوى الكلوكوز قبل الحقن القاعدي. أثبتت فعالية وحدة التحكم المقترحة ، والتي تمثل جرعة الأنسولين ، عن طريق محاكاة نموذج ببركمان مع وحدة تحكم مصممة عبر برنامج MATLAB وتوضح النتيجة قدرة ومتانة وحدة التحكم المقترحة.

Listing 1 - 10 of 84 << page
of 9
>>
Sort by
Narrow your search

Resource type

article (84)


Language

English (69)

Arabic and English (10)

Arabic (3)


Year
From To Submit

2019 (7)

2018 (11)

2017 (15)

2016 (8)

2015 (6)

More...