Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userDeveloping a position estimation algorithmin GNSS-Precise Point Positioning technique depending on Extended Kalman Filter
تطوير خوارزمية تقدير الموقع باستخدام تقنية التموضع النقطي الدقيق لقياسات نظم الملاحة العالمية بالأقمار الصناعية اعتماداً على مرشح كالمن الموسع
1128
0 49
0
(
0
)
Added by
Tishreen University ورقة بحثية
Publication date
2015
fields
topography
and research's language is
العربية
Created by
Shamra Editor
Ask ChatGPT about the research
تستخدم تقنية التموضع النقطي الدقيق الخوارزميات التكرارية للحصول على حل المسألة الملاحية، و ذلك نتيجة قصور طريقة التربيعات الصغرى التقليدية على مواكبة المتطلبات المتزايدة للحصول على مخرجات المعالجة من الكم الهائل للبيانات المزوّدة من نظم الملاحة العالمية بالأقمار الصناعية بالسرعة و الجودة المطلوبة للتطبيقات الجيوديزية و المساحية المختلفة. مرشح كالمن الموسع يعد المقاربة الأفضل للحل لكنه بالإضافة إلى المعرفة بالقياسات و نماذج الأرصاد الخاصة بها، فإنه يتطلب أيضاً المعرفة بالحالة الفيزيائية لمسألة التقدير مثل ديناميكية جهاز الاستقبال و خصائص الإشارة المستقبلة، و التقدير المناسب لشروطه الابتدائية. يتضمن البحث اقتراحاً رياضياً لتعديل طريقة استخدام مرشح كالمن الموسع في تقنية التموضع النقطي الدقيق لتقليل الأثر السلبي لزمن التقارب ضمن الشروط الابتدائية للخوارزمية التكرارية للمرشح، و عرض لنتائج تجربة تعديل طريقة الاستخدام تلك على دقة تقدير الموقع. و يؤكد البحث على ضرورة استخدام التعديل المقترح على خوارزمية تقدير الموقع على الرغم من زيادة زمن المعالجة نسبياً.
Precise point positioning technique uses recursive algorithms to solve the navigation problem. In fact, traditional least square method doesn’t meet the requiredassessments of processing speed, and quality in different geodetic and surveying applications,due tobig amount of output processing data provided by global navigation satellite systems. Extended Kalman filter is considered as optimal solution approach of the navigation problem. This filter requiresthe knowledge of measurements, its observational models, and physical state for estimation problem like: (receiver dynamic, received signals characters, and suitable estimation of its initial conditions). Research refers to a mathematical suggestion, which reduce the negative effect of convergence time at EKF initial conditions. This work also shows how a position estimation accuracy affected by the suggested modification of using EKF in PPP, and supporting the use ofthis modification in position estimation field, in spite of increasing processing time.
References used
MARTIN, I.GNSS Precise Point Positioning:The enhancement with GLONASS. School of Civil Engineering and Geosciences Newcastle University, Newcastle, 2013, 244
MARTÍN, A.; ANQUELA, A.B.; CAPILLA, R.; BERNÉ, J. L.PPP Technique Analysis Based On Time Convergence, Repeatability, IGS Products, Different Software Processing And GPS+Glonass Constellation. Journal Of Surveying Engineering, Vol.137, NO. 3, 2011, 99-108
LE, A.;TEUNISSEN, P. Optimal Recursive Least-Squares Filtering Of GPS Pseudorange Measurements. Springer, Verlag, 2008,540
rate research
Read More
This research deals with improving the efficiency of solar photovoltaic (PV) power
systems using a Fuzzy Logic Controller (FLC) for Maximum Power Point Tracking
(MPPT), to control the duty cycle of DC-DC Voltage Converter, to achieve the
photovolt
aic system works at a Maximum Power Point under different atmospheric
changes of the solar insolation and ambient temperature. In this context, this research
presents a new model for FLC developed in Matlab/Simulink environment. The proposed
model for the controller is based on the conventional Perturb and Observe (P&O)
technique. Where, in similar to the conventional P&O technique, the changes in the Power
and tension of photovoltaic power system, are considered as the input variables of the
proposed controller, while the output variable is the change in the duty cycle. The main
advantage of the developed controller FLC, based on the considering the change in the
duty cycle has a Variable Step Size, and directly related to the changes in the power and
tension of the Photovoltaic system. Which make it possible to overcome the problem of
fixed Step Size in the change of the duty cycle in the conventional MPPT- P&O Controller
based on P&O technique. The MPPT- P&O Fuzzy, works by a variable step size achieve a
fast speed response and high efficiency for tracking the MPP point under sudden and
rapidly varying atmospheric conditions, compared with the conventional MPPT- P&O. The
simulation results completed in Matlab/Simulink environment, showed the best
performance of developed MPPT- P&O Fuzzy controller in tracking the MPP by achieving
a better dynamic performance and high accuracy, compared with the use of the
conventional MPPT- P&O under different atmospheric changes.
The objective of this research is to model the dynamic
characteristics of lead-acid batteries taking into account their
fundamental phenomena (the electric double-layer, the charge
transfer and diffusion phenomenon due to oxidation and reduction
reactions). The value of the equivalent circuit elements used in
modeling is determined experimentally using a pulsed discharge of
the battery.
Recent technological advances have greatly improved the performance and features
of computers and mobile systems. This improvements leads to increase in power
consumption which makes the task of managing their power consumption necessary. The
proc
essor considered as one of the most power consuming elements in the system so, this
research aims to develop a new method for power management in multicore architecture
which support most of the modern electronics. Power management techniques is an
important field in multicore studies because it must balance between the demanding needs
for higher performance/throughput and the impact of aggressive power consumption and
negative thermal effects. Many techniques have been proposed in this research like
(Dynamic Voltage and Frequency Scaling (DVFS), Asymmetric cores, Thread motion,
variable size cores, core fusion) then after we summarized comparing table which clarifies
the pros and cons of these techniques, we proposed a new technique for power
management in multi-core processors implements the best of these techniques .
Knowledge graph embedding, representing entities and relations in the knowledge graphs with high-dimensional vectors, has made significant progress in link prediction. More researchers have explored the representational capabilities of models in rece
nt years. That is, they investigate better representational models to fit symmetry/antisymmetry and combination relationships. The current embedding models are more inclined to utilize the identical vector for the same entity in various triples to measure the matching performance. The observation that measuring the rationality of specific triples means comparing the matching degree of the specific attributes associated with the relations is well-known. Inspired by this fact, this paper designs Semantic Filter Based on Relations(SFBR) to extract the required attributes of the entities. Then the rationality of triples is compared under these extracted attributes through the traditional embedding models. The semantic filter module can be added to most geometric and tensor decomposition models with minimal additional memory. experiments on the benchmark datasets show that the semantic filter based on relations can suppress the impact of other attribute dimensions and improve link prediction performance. The tensor decomposition models with SFBR have achieved state-of-the-art.
This paper discuss the Laser induced breakdown
spectroscopy (LIBS) by using Nd:YAG which is a high energy
pulsed Laser . The laser radiation is focused on solid targets which
are samples of red Copper (99.5%). Most important Plasma
parameters which are electron temperature and density was
measured.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
