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Control of a drone: study and analysis of the robustness

100%

Zemalache K. M. , Beji L. , Maaref H.

Journal of Automation Mobile Robotics and Intelligent Systems

2008

tom Vol. 2, No. 1

33-42

The work describes an automatically on-line Self-Tunnable Fuzzy Interference Systems (STFIS) of a new configuration of mini-flying called XSF (X4 Stationary Flyer) drone. A Fuzzy controller based on-line optimization of a zero order Takagi-Sugeno fuzzy interference system (FIS) by a back propagation like algorithm is successfully applied. It is used to minimize a cost function that is made up of a quadratic error term and a weight decay term that prevents an excessive growth of parameters. Thus, we carried out control for helical trajectories by using the STFIS technique. This permits to prove the effectiveness of the proposed control law. Simulation results and a comparison with a Static Feedback Linearization controller (SFL) are presented and discussed. We studied the robustness of the two used controllers in the presence of disturbances. We presented the case of an engine breakdown as well as a gust of wind and taking into account white noise disturbances.

Up-conversion fluorescence dynamics in Er3+/Yb3+ co-doped tellurite glasses

100%

Cherif A. , Kanoun A. , Maaref H.

Optica Applicata

2011

tom Vol. 41, nr 1

235--245

The infrared to visible conversion in zinc tellurite glasses (TZG), activated by Er3+ ions and sensitized by Yb3+ ions, has been investigated under 980 nm pulsed laser excitation. The up-conversion mechanism was studied by means of time-resolved luminescence spectroscopy. A model for the dynamics of frequency up-conversion in Er3+/Yb3+ co-doped TZG based on the rate equations was proposed. The dynamics of the up-converted emissions were studied to evaluate energy rates between Er3+ and the Yb3+ ions, and the rate excited state absorption (ESA) in Er3+ ions.