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Home > Dynamics Numerical Optimization and Control of Dynamic Soaring Maneuvers for a Morphing Capable Unmanned Aerial Vehicle

Dynamics Numerical Optimization and Control of Dynamic Soaring Maneuvers for a Morphing Capable Unmanned Aerial Vehicle

Thesis Info

Access Option

External Link

Author

Mir, Imran

Program

PhD

Institute

National University of Sciences & Technology

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Computational Science & Engineering

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12016/1/Imran%20Mir%20Computational%20science%202018%20nust%20isb%20prr.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725930328

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Dynamicsoaringisaversatilemaneuverexecutedtoacquireenergyavailable in the atmospheric wind shears. For UAVs, dynamic soaring maneuvers have mostly been confined in literature to fixed configurations. In order to analyzetheextenttowhichdynamicsoaringisinfluencedbydifferentmorphologies, aninnovativeconceptofintegratingdynamicsoaringwithmorphingcapabilities is introduced in this research. Through simulations, two major studies were performed. One of them analyzed the impact of span morphology and the other of sweep morphology on dynamic soaring parameters. An Unmanned Air Vehicle(UAV) with standard wing-tail configuration is considered. The aerodynamic modeling is based on empirical estimation procedure duly validate dwit numerical Vortex Lattice Method(VLM).Three-dimensional point-mass UAV equations of motion and nonlinear wind gradient profile are used to model the flight dynamics. The trajectory optimization problem is formulated as an optimal control problem using hp-adaptive Guassian quadrature collocation technique. Optimal soaring trajectories are generated for both morphologies. Parametriccharacterizationofthekeyperformanceparametersisperformed to determine the optimal platform configuration during various phases of the maneuver. The comparison of morphing ability during flight is compared with its fixed-wing counterpart. Simulation results demonstrate the benefits of extending soaring maneu vers to morphing configurations and its viability for onboard utilization. Results indicate 15% lesser required wind shear by the proposed span morphology and 14% lesser required wind shear by the proposed sweep morphology, in comparison to their respective fixed wing counterparts. This shows that the morphing UAVcanperformdynamicsoaringinanenvironment,wherefixedconfiguration UAVs might not, because of lesser available wind shears. Apart from this, span morphology reduced drag by 15%, lift requirement by 11% and angle of attack requirement by 20%, whereas increased the maximum velocity by 6.2%, normalized energies by 9% and improved loitering parameters (approximately 10%), in comparison to fixed span configurations. Similarly, sweep morphology guaranteed 20% drag reduction, 16% lesser angle of attack requirement and improved loitering performance over the fixed sweep configurations. The stability analysis of the nonlinear system along the optimal trajectory is then performed utilizing both linear (Floquettheory) and nonlinear (Contraction theory) techniques. Stability of dynamic soaring orbits is important since the trajectories can get disturbed by a strong gust or crosswinds causing the UAV to veer off-course. Although control system can be designed, a stable orbit can reduce the control effort and power. The problem of analyzing stability is treated from the context of a periodic coefficient system. The stability analysis revealed that a closed-loop control is necessary as the system dynamics are inherently unstable. AgeometricnonlinearcontrollabilityanalysisofUAVunderdynamicsoaring conditions is then performed. To achieve such an objective, the state-of-theartmathematicaltoolsofnonlinearcontrollabilityareutilized. Thecontrollability of a flying vehicle along that optimal soaring trajectory is analyzed. More im portantly, the geometric nonlinear controllability characteristics of generic flight dynamics is analyzed in the presence and absence of wind shear to provide a controllability explanation for the role of wind shear in the physics of dynamic soaring flight. It is found that the wind shear is instrumental in ensuring controllability as it allows the UAV attitude controls (pitch and roll) to play the role of thrust in controlling the flight path angle. The presented analysis represents a controllability-based mathematical proof for the energetics of flight physics.
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آٹھواں باب: روحانی نظام

یہودی روحانیت کے ابتدائی مظاہر

باب ہشتم کے اہم نکات

  1. یہودی روحانیت کا تعارف۔
  2. حزقی ایل کے روحانی تجربات۔
  3. مرکبہ یہودیت کا فروغ۔
  4. حسیدی اشکناز کا تعارف۔
  5. تخلیق کائنات کا بیان۔
  6. صفر یتزیرا، بہیر اور زوہر کا بیان۔
  7. قبالہ، اس کی ذیلی تحریکیں اور حسیدیت کا تعارف۔
     روحانیت، باطنیت، سریت یا تصوف کی اصطلاحیں عموماً ایک ایسے مخفی نظام کو بیان کرنے کے لیے استعمال کی جاتی ہیں جو مادی دنیا سے مختلف ہوتے ہوئے بھی اپنا تعلق اس سے جوڑے رکھتا ہے۔ یہودیت کا روحانی نظام بھی کم و بیش انہیں صفات کا حامل ہے۔ خدا سے تعلق، تخلیقِ کائنات پر گفتگو اور مقدس کتب کے روحانی معانی کی تلاش ایک یہودی صوفی کا نصب العین ہے۔ یہودیت کے روحانی ادوار کو زمانی اعتبار سے چار حصوں میں تقسیم کیا جا سکتا ہے:
  1. بائیبل کا دور جس میں روحانی نظریات اور تحریکیں تو دکھائی نہیں دیتیں لیکن اس دور کے مذہبی تجربات نے بعد میں آنے والے صوفیا کو روحانیت سے روشناس کروایا۔
  2. ہیکل کی دوسری تباہی کا دور جس میں ایسے روحانی نظریات وجود پانے لگے تھے جن کی بنیاد مذہب پر رکھنے کی کوشش کی جا رہی تھی۔
  3. قبالہ کا دور جس میں منظم انداز میں روحانی تعلیمات کو بحیثیتِ مجموعی بیان کیا جا رہا تھا۔
  4. حسیدی دور جس میں روحانیت سے نئے مذہبی محسوسات نے جنم لیا۔[1]

 یہودی روحانیت میں زیادہ تر مذہبی تجربات کی کوئی عقلی توجیہ پیش کرنے کی ضرورت نہیں سمجھی جاتی کیونکہ یہ خیال کیا جاتا ہے کہ ان تجربات تک عقل کی رسائی ممکن نہیں ہے۔ اس کا یہ مطلب بھی نہیں ہے کہ یہ تجربات...

بدائع التفاسیرکی روشنی میں سماجی حسد سے بچنے کے تدابیر کا تحقیقی مطالعہ

Like all the physical diseases, which are fatal for a body, all the ethical weaknesses, like avarice, rampage, and malignity are also most harmful for a man. But, amidst these, envy is the malady which, apart from personally, also affects badly the whole society. Individually, the victim of envy suffers from a high psychological troubles and inner becomes subjected to many diseases. The reaction of envy firstly attacks the envier, rather than the envied person. There can never come affection or consolidation in the society which contains this moral disease: envy. That is why, the Holy Qur┐’n directs us to seek refuge from the envy of an envier. The Holy Qur┐’n says : ( Say, I seek refuge) from the evil of an envier when he envies. The Holy Prophet said: Avoid yourselves from envy, it eats one’s good deeds such as a fire eats the wood.

Determinants of Stress Causing Dissatisfaction Among University Teachers of Khyber Pakhtunkhwa, Pakistan

Stress has been introduced as a creatively ambiguous term that brings detrimental consequences to both individuals as well as the organization. Stress if left unchecked may result in burnout that is the stage where person develops feelings of exhaustion, lack of accomplishment and depersonalization. The study is an effort to find out the pertinent stressors of public and private sector universities’ faculty members in Peshawar. Another objective of the research is to find out the level of stress among the faculty members of public and private universities. The study tends to find that stress is more in private or public sector Various studies have brought in front number of variables both individual as well as organizational inciting stress out of which work overload, Rewards, Student’s interaction, collegial support, self efficacy, but the greater achievement was to identify those factors which were either considered secondary in previous researches or were neglected; were identified here in first instance like; leadership style, organizational politics, distributive justice and procedural justice and further these pertinent factors came out to be very important in causing stress. The scope of the study is limited to the business management universities/institutions who have got degree awarding status only; therefore the population includes eighteen universities of Peshawar recognized by Higher Education Commission. Through Simple random sampling 398 faculty members were selected and contacted through questionnaire instrument. The questionnaire was pilot tested. The reliability of the pilot test (.94 alpha) revealed the justification for the further data collection. The analysis of data indicated the following major findings: · The faculty serving the public as well as private sector universities of Peshawar experience stress with varying magnitude. In public sector the level of stress is comparatively higher than the private sector. Whereas for both sectors stressors relating to work overload are the prime stress instigators.Stress in Private and Public Sector Universities · Universities must also review their policies regarding employee maintenance like compensation, distributive as well as procedural justice that is needed to be ensured for the purpose of reducing employee stress and frustration. · Communication dependent problems were identified as student faculty interaction (SFI) and collegial social interaction (CSI) which are causing stress and are to be addressed by the universities. · Other then the reward procedural (PJ) and distributive justice (DJ) was identified as a major factor in causing stressful environment among faculty members. Also the additional factors reported by the faculty includes Limited technical support for computer problems, working with new administrators, Insufficient classrooms and office space for new faculty, Budget cutbacks by the governments. Stress among teachers makes the dream of quality education as an infertile reality by placing teachers venerable to various health risk, therefore the factors inciting stress among teachers should be explored with a view to either eradicate them altogether or at least coping mechanism should be developed in order to deal stressors effectively. Based on the findings of the data analysis the researcher’s recommendations include the following: · Stress management training programs and seminars for the faculty. · Redesigning jobs in a manner so that there is reward dynamism on one side and clear career path of promotion and development on the other. · Attractive employee maintenance; like compensation, distributive as well as procedural justice needed to be rejuvenated and applied. Administration should take steps in providing procedural and distributive justice to their employees for ensuring reduction in stress. Furthermore, steps should be taken to reduce discrimination amongst teachers for the purpose of job promotion, reward, and performance evaluation.