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George Nikolakopoulos

Bio: George Nikolakopoulos is an academic researcher from Luleå University of Technology. The author has contributed to research in topics: Computer science & Control theory. The author has an hindex of 28, co-authored 258 publications receiving 3732 citations. Previous affiliations of George Nikolakopoulos include Nera & University of Patras.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the control problem of an unmanned quadrotor in an indoor environment where there is lack of absolute localization data is addressed based on an attached Inertia Measurement Unit.
Abstract: This article addresses the control problem of an unmanned quadrotor in an indoor environment where there is lack of absolute localization data. Based on an attached Inertia Measurement Unit, a sona ...

328 citations

Journal ArticleDOI
TL;DR: In this article, a Switching Model Predictive Attitude Controller for an Unmanned quadrotor Helicopter subject to atmospheric disturbances is presented, and the proposed control scheme is computed based on the predicted attitude.

308 citations

Journal ArticleDOI
TL;DR: A comprehensive literature review on vision based applications for UAVs focusing mainly on current developments and trends is presented and the concept of fusion multiple sensors is highlighted.
Abstract: During last decade the scientific research on Unmanned Aerial Vehicless (UAVs) increased spectacularly and led to the design of multiple types of aerial platforms. The major challenge today is the development of autonomously operating aerial agents capable of completing missions independently of human interaction. To this extent, visual sensing techniques have been integrated in the control pipeline of the UAVs in order to enhance their navigation and guidance skills. The aim of this article is to present a comprehensive literature review on vision based applications for UAVs focusing mainly on current developments and trends. These applications are sorted in different categories according to the research topics among various research groups. More specifically vision based position-attitude control, pose estimation and mapping, obstacle detection as well as target tracking are the identified components towards autonomous agents. Aerial platforms could reach greater level of autonomy by integrating all these technologies onboard. Additionally, throughout this article the concept of fusion multiple sensors is highlighted, while an overview on the challenges addressed and future trends in autonomous agent development will be also provided.

255 citations

Proceedings ArticleDOI
17 Jul 2013
TL;DR: In the presented approach both the quadrotor's attitude model and the proposed non-linear Proportional squared (P2) control algorithm have been implemented in the quaternion space, without any transformations and calculations in the Euler's angle space or DCM.
Abstract: The aim of this article is to present a novel quaternion based control scheme for the attitude control problem of a quadrotor A quaternion is a hyper complex number of rank 4 that can be utilized to avoid the inherent geometrical singularity when representing rigid body dynamics with Euler angles or the complexity of having coupled differential equations with the Direction Cosine Matrix (DCM) In the presented approach both the quadrotor's attitude model and the proposed non-linear Proportional squared (P2) control algorithm have been implemented in the quaternion space, without any transformations and calculations in the Euler's angle space or DCM Throughout the article, the merits of the proposed novel approach are being analyzed and discussed, while the efficacy of the suggested novel quaternion based controller are being evaluated by extended simulation results

215 citations

Journal ArticleDOI
TL;DR: The utilization of structural control systems for alleviating the responses of civil engineering structures, under the effects of different kinds of dynamics loadings, has become a standar....
Abstract: Nowadays the utilization of structural control systems for alleviating the responses of civil engineering structures, under the effects of different kinds of dynamics loadings, has become a standar ...

190 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Christopher M. Bishop1
01 Jan 2006
TL;DR: Probability distributions of linear models for regression and classification are given in this article, along with a discussion of combining models and combining models in the context of machine learning and classification.
Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

10,141 citations

Posted Content
TL;DR: This paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies which are adaptive, distributed, asynchronous, and verifiably correct.
Abstract: This paper presents control and coordination algorithms for groups of vehicles. The focus is on autonomous vehicle networks performing distributed sensing tasks where each vehicle plays the role of a mobile tunable sensor. The paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies. The resulting closed-loop behavior is adaptive, distributed, asynchronous, and verifiably correct.

2,198 citations