Introducing Contextual Awareness Within the State Estimation Process

Introducing Contextual Awareness Within the State Estimation Process
Author: Alexandre Ravet
Publisher:
Total Pages: 193
Release: 2015
Genre:
ISBN:

Prevalent approaches for endowing robots with autonomous navigation capabilities require the estimation of a system state representation based on sensor noisy information. This system state usually depicts a set of dynamic variables such as the position, velocity and orientation required for the robot to achieve a task. In robotics, and in many other contexts, research efforts on state estimation converged towards the popular Bayes filter. The primary reason for the success of Bayes filtering is its simplicity, from the mathematical tools required by the recursive filtering equations, to the light and intuitive system representation provided by the underlying Hidden Markov Model. Recursive filtering also provides the most common and reliable method for real-time state estimation thanks to its computational efficiency. To keep low computational complexity, but also because real physical systems are not perfectly understood, and hence never faithfully represented by a model, Bayes filters usually rely on a minimum system state representation. Any unmodeled or unknown aspect of the system is then encompassed within additional noise terms. On the other hand, autonomous navigation requires robustness and adaptation capabilities regarding changing environments. This creates the need for introducing contextual awareness within the filtering process. In this thesis, we specifically focus on enhancing state estimation models for dealing with context-dependent sensor performance alterations. The issue is then to establish a practical balance between computational complexity and realistic modelling of the system through the introduction of contextual information. We investigate on achieving this balance by extending the classical Bayes filter in order to compensate for the optimistic assumptions made by modeling the system through time-homogeneous distributions, while still benefiting from the recursive filtering computational efficiency. Based on raw data provided by a set of sensors and any relevant information, we start by introducing a new context variable, while never trying to characterize a concrete context typology. Within the Bayesian framework, machine learning techniques are then used in order to automatically define a context-dependent time-heterogeneous observation distribution by introducing two additional models: a model providing observation noise predictions and a model providing observation selection rules.The investigation also concerns the impact of the training method we choose. In the context of Bayesian filtering, the model we exploit is usually trained in the generative manner. Thus, optimal parameters are those that allow the model to explain at best the data observed in the training set. On the other hand, discriminative training can implicitly help in compensating for mismodeled aspects of the system, by optimizing the model parameters with respect to the ultimate system performance, the estimate accuracy. Going deeper in the discussion, we also analyse how the training method changes the meaning of the model, and how we can properly exploit this property. Throughout the manuscript, results obtained with simulated and representative real data are presented and analysed.

Author:
Publisher: Springer Nature
Total Pages: 206
Release:
Genre:
ISBN: 3031588789

Location- and Context-Awareness

Location- and Context-Awareness
Author: Thomas Strang
Publisher: Springer Science & Business Media
Total Pages: 389
Release: 2005-05-12
Genre: Computers
ISBN: 3540258965

Context-awareness is one of the drivers of the ubiquitous computing paradigm. Well-designed context modeling and context retrieval approaches are key p- requisites in any context-aware system. Location is one of the primary aspects of all major context models — together with time, identity and activity. From the technical side, sensing, fusing and distributing location and other context information is as important as providing context-awareness to applications and services in pervasive systems. Thematerialsummarizedinthisvolumewasselectedforthe1stInternational Workshop on Location- and Context-Awareness (LoCA 2005) held in coope- tion with the 3rd International Conference on Pervasive Computing 2005. The workshop was organized by the Institute of Communications and Navigation of the German Aerospace Center (DLR) in Oberpfa?enhofen, and the Mobile and Distributed Systems Group of the University of Munich. During the workshop, novel positioning algorithms and location sensing te- niques were discussed, comprising not only enhancements of singular systems, like positioning in GSM or WLAN, but also hybrid technologies, such as the integration of global satellite systems with inertial positioning. Furthermore, - provements in sensor technology, as well as the integration and fusion of sensors, were addressed both on a theoretical and on an implementation level. Personal and con?dential data, such as location data of users, have p- found implications for personal information privacy. Thus privacy protection, privacy-oriented location-aware systems, and how privacy a?ects the feasibility and usefulness of systems were also addressed in the workshop.

Exploration of State Estimation

Exploration of State Estimation
Author: Guillaume Goffaux
Publisher: LAP Lambert Academic Publishing
Total Pages: 388
Release: 2010-05
Genre:
ISBN: 9783838360355

State estimation plays a key role in the knowledge of characteristic variables of a system. By combining information from hardware sensor measurements and mathematical models, it improves the knowledge of the relevant variables used for advanced control or monitoring strategies. Moreover, a lot of state estimation techniques exist and try to improve accuracy despite uncertainties. In this context, this work provides an overview of useful state estimation techniques and gives extensions with robustness to uncertainties as objective. Two application fields are investigated with their own objectives in terms of safety and accuracy : safe vehicle positioning and bioprocesses. This book is divided into three parts. The first part introduces state estimation and describes popular techniques as Kalman filter and moving-horizon filter. Recent methods are also introduced like particle filtering or interval estimation. The next two parts are dedicated to the applications and the developed extensions. This book has a tutorial objective and can be dedicated to engineers in Automatic Control or to all who look for an advanced introduction to the state space exploration.

Handbook of Dynamic Data Driven Applications Systems

Handbook of Dynamic Data Driven Applications Systems
Author: Erik Blasch
Publisher: Springer
Total Pages: 734
Release: 2018-11-13
Genre: Computers
ISBN: 3319955047

The Handbook of Dynamic Data Driven Applications Systems establishes an authoritative reference of DDDAS, pioneered by Dr. Darema and the co-authors for researchers and practitioners developing DDDAS technologies. Beginning with general concepts and history of the paradigm, the text provides 32 chapters by leading experts in10 application areas to enable an accurate understanding, analysis, and control of complex systems; be they natural, engineered, or societal: Earth and Space Data Assimilation Aircraft Systems Processing Structures Health Monitoring Biological Data Assessment Object and Activity Tracking Embedded Control and Coordination Energy-Aware Optimization Image and Video Computing Security and Policy Coding Systems Design The authors explain how DDDAS unifies the computational and instrumentation aspects of an application system, extends the notion of Smart Computing to span from the high-end to the real-time data acquisition and control, and manages Big Data exploitation with high-dimensional model coordination.

EUC 2004

EUC 2004
Author: Laurence T. Yang
Publisher: Springer Science & Business Media
Total Pages: 1135
Release: 2004-08-18
Genre: Computers
ISBN: 354022906X

This book constitutes the refereed proceedings of the International Conference on Embedded and Ubiquitous Computing, EUC 2004, held in Aizu-Wakamatsu City, Japan, in August 2004. The 104 revised full papers presented were carefully reviewed and selected from more than 260 submissions. The papers are organized in topical sections on embedded hardware and software; real-time systems; power-aware computing; hardware/software codesign and systems-on-chip; mobile computing; wireless communication; multimedia and pervasive computing; agent technology and distributed computing, network protocols, security, and fault-tolerance; and middleware and peer-to-peer computing.

Computer Aided State Estimation of Electric Power Network

Computer Aided State Estimation of Electric Power Network
Author: Subramanian Srikrishna
Publisher: BrownWalker Press
Total Pages: 256
Release: 2020-08-01
Genre: Technology & Engineering
ISBN: 1627347496

Computer Aided State Estimation of Electric Power Networks is a fundamental introduction to the topic of state estimation at an advanced textbook level for teaching a course at either the graduate or undergraduate level, as well as for Post Graduate students and Research Scholars who want to review of the latest techniques and best mathematical approaches for estimating the state of a general system. Theory as well as practice of Distribution System State Estimation (DSSE) is covered with imperative rigidity. The authors present the theory of state estimation clearly providing the right amount of essential information and linked reports in order to enable the researchers and graduate students to apply state estimation techniques across a variety of fields in power systems engineering. A prerequisite knowledge of basic power system operation, control, data acquisition and measurement, in addition to basic statistics is helpful in understanding the book. Key Features include: • Advanced Topics based on Cloud Computing and Standards used for Preparation of Smart Grid • Provides Entire Coding Information for Estimating the State Estimation Topology Performance • Enables both the Researchers and Graduate Students for Pursuing their Research Projects • Covers the Important Topics on Data Attacks and Solution Strategy • Provides an Introduction to Distribution System State Estimation This book includes new contents like Distribution System State Estimation, Data Attacks, Defense strategies, with an introduction to large scale systems based on cloud computing, and an MATLAB training package for graduate students

Quality of Service in Heterogeneous Networks

Quality of Service in Heterogeneous Networks
Author: Novella Bartolini
Publisher: Springer Science & Business Media
Total Pages: 809
Release: 2009-11-09
Genre: Computers
ISBN: 3642106242

This volume presents the proceedings of the 6th International ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness and of the Third International ICST Workshop on Advanced Architectures and Algorithms for Internet DElivery and Applications. Both events were held in Las Palmas de Gran Canaria in November 2009. To each of these events is devoted a specific part of the volume. The first part is dedicated to the proceedings of ICST QShine 2009. The first four chapters deal with new issues concerning the quality of service in IP-based telephony and multimedia. A second set of four chapters addresses some important research problems in mul- hop wireless networks, with a special emphasis on the problems of routing. The following three papers deal with recent advances in the field of data mana- ment and area coverage in sensor networks, while a fourth set of chapters deals with mobility and context-aware services. The fifth set of chapters contains new works in the area of Internet delivery and switching systems. The following chapters of the QShine part of the volume are devoted to papers in the areas of resource management in wireless networks, overlay, P2P and SOA arc- tectures. Some works also deal with the optimization of quality of service and energy consumption in WLAN and sensor networks and on the design of a mobility support in mesh networks.

Context-Aware Systems and Applications, and Nature of Computation and Communication

Context-Aware Systems and Applications, and Nature of Computation and Communication
Author: Phan Cong Vinh
Publisher: Springer
Total Pages: 248
Release: 2018-03-15
Genre: Computers
ISBN: 3319778188

This book constitutes the refereed post-conference proceedings of the International Conferences ICCASA and ICTCC 2017, held in November 2017 in Tam Ky City, Vietnam. The 23 revised full papers presented were carefully selected from 31 submissions. The papers of ICCASA cover a wide spectrum in the area of context-aware-systems. CAS is characterized by its self- facets such as self-organization, self-configuration, self-healing, self-optimization, self-protection used to dynamically control computing and networking functions. The papers of ICTCC cover formal methods for self-adaptive systems and discuss natural approaches and techniques for computation and communication.