George Nikolakopoulos

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This study addresses the control problem of an unmanned quadrotor in an indoor environment where there is lack of absolute localisation data. Based on an attached inertia measurement unit, a sonar and an optic-flow sensor, the state vector is estimated using sensor fusion algorithms. A novel switching model predictive controller is designed in order to(More)
In this paper the development and experimental verification of mobile client-centric networked controlled system is presented. The feedback control loop is closed over a General Purpose Radio Service (GPRS) communication channel, between the plant and the controller. The inserted delays from the communication network, are time-varying, degrade the system(More)
The power awareness issue is the primary concern within the domain of Wireless Sensor Networks (WSNs). Most power dissipation ocurrs during communication, thus routing protocols in WSNs mainly aim at power conservation. Moreover, a routing protocol should be scalable, so that its effectiveness does not degrade as the network size increases. In response to(More)
— In this article the design of an intelligent robust controller for a Micro–Actuator (µ−A) is presented. The µ−A is composed of a micro–capacitor, whose one plate is clamped while its other flexible plate's motion is constrained by hinges acting as a combination of springs and dashpots. The distance of the plates is varied by the applied voltage between(More)
In this article the control problem of a micro-actuator (µ − A) is considered. The µ − A is composed of a micro-capacitor, whose one plate is clamped while its other flexible plate's motion is constrained by hinges acting as a combination of springs and dashpots. The distance of the plates is varied by the applied voltage between them. The flexibility of(More)
In this article a scheme for image transmission over Wireless Sensor Networks (WSN) with an adaptive compression factor is introduced. The proposed control architecture affects the quality of the transmitted images according to: (a) the traffic load within the network and (b) the level of details contained in an image frame. Given an approximate(More)
In this paper a vision-based integrated system, relying on Active Contour Models (ACM) will be presented. ACM is a popular technique for extracting the object's boundaries based on the a priori knowledge of the object-shape. The algorithm is implemented in industrial parts of circular cross-section with undefined radius. The objective of ACM is to define(More)
— A Constrained Finite Time Optimal Controller (CFTOC) for attitude set–point maneuvers of an Unmanned Quadrotor Helicopter (UqH) operating under severe wind conditions is the subject of this article. The UqH's nonlinear dynamics is linearized in various operating points resulting in a set of piecewise models. The CFTOC is designed for set-point maneuvers(More)