George Nikolakopoulos

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This article addresses the control problem of quadrotors in environments where absolute-localization data (GPS, positioning from external cameras) is inadequate. Based on an attached IMU and an optical flow sensor the quadrotor's translational velocity is estimated using an Extended Kalman Filter. Subject to the velocity measurements, the roll, pitch and(More)
In this article, a novel on-line path planning algorithm for an articulated vehicle, moving in a partially known and sensory based reconstructed environment, and relying on Model Predictive Control will be presented. The proposed algorithm belongs to the family of bug like path planning algorithms and has the capability to take under consideration the real(More)
In this article a switching model predictive control scheme for an articulated vehicle under varying slip angles is being presented. For the non-holonomic articulated vehicle, the non-linear kinematic model that is able to take under consideration the effect of the slip angles is extracted. This model is transformed into an error dynamics model, which in(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)
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 article a survey on the different technologies in the area of Underwater Wireless Sensor Networks (UWSN) will be presented. The characteristics of these networks are different from those found in the terrestrial ones, while their architecture is vulnerable to various issues such as large propagation delays, mobility of floating sensor nodes, limited(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 paper the design and the experimental verification of a Constrained Finite Time Optimal (CFTO) control scheme for the attitude control of an Unmanned Quadrotor Helicopter (UqH) subject to wind gusts is being presented. In the proposed design the UqH has been modeled by a set of Piecewise Affine (PWA) linear equations while the wind gusts effects are(More)