Flatness Control: Application to a Fractional Thermal System

Author(s):  
Pierre Melchior ◽  
Mikae¨l Cugnet ◽  
Jocelyn Sabatier ◽  
Alain Oustaloup

This paper concerns the application of flatness principle to fractional systems. As soon as the path has been obtained by flatness, a new robust path tracking based on CRONE control is presented. The flatness concept in path planning is used when the trajectory is fixed (in space and in time), to determine the controls to apply without having to integrate any differential equations. A lot of developments have been made but, in the case of non integer differential systems (or fractional systems), few developments are still to be made. So, the aim of this paper is to apply flatness principle to a fractional system and to define a robust path tracking by CRONE control strategy. Firstly, we remind flatness principle definitions used in control’s theory. We study the fractional systems dynamic inversion. A robust path tracking based on CRONE control is presented. Finally, simulations with two different controllers (PID and CRONE) illustrate the path tracking robustness.

2011 ◽  
Vol 44 (1) ◽  
pp. 10818-10823 ◽  
Author(s):  
Stéphane Victor ◽  
Pierre Melchior ◽  
Rachid Malti ◽  
Alain Oustaloup

Author(s):  
Amel Benchellal ◽  
Thierry Poinot ◽  
Jean-Claude Trigeassou

Heat transfer problems obey to diffusion phenomenon. They can be modelled with the help of fractional systems. The simulation of these particular systems is based on a fractional integrator where the non integer behaviour acts only on a limited spectral band. Starting from frequential considerations, a more general approximation of the fractional system is proposed in this communication. It makes it possible to define a state-space model for simulation of transients, and to carry out an output-error technique in order to estimate the parameters of the model. A real application on a thermal system is presented to illustrate the advantages of the proposed model.


2013 ◽  
Vol 76 (1) ◽  
pp. 447-457 ◽  
Author(s):  
Najah Yousfi ◽  
Pierre Melchior ◽  
Patrick Lanusse ◽  
Nabil Derbel ◽  
Alain Oustaloup

2016 ◽  
Vol 24 (4) ◽  
pp. 659-672 ◽  
Author(s):  
Elena Ivanova ◽  
Xavier Moreau ◽  
Rachid Malti

The interest of studying fractional systems of second order in electrical and mechanical engineering is first illustrated in this paper. Then, the stability and resonance conditions are established for such systems in terms of a pseudo-damping factor and a fractional differentiation order. It is shown that a second-order fractional system might have a resonance amplitude either greater or less than one. Moreover, three abaci are given allowing the pseudo-damping factor and the differentiation order to be determined for, respectively, a desired normalized gain at resonance, a desired phase at resonance, and a desired normalized resonant frequency. Furthermore, it is shown numerically that the system root locus presents a discontinuity when the fractional differentiation order is an integral number.


2011 ◽  
Vol 17 (2) ◽  
pp. 194-213 ◽  
Author(s):  
Guilherme V. Raffo ◽  
Manuel G. Ortega ◽  
Francisco R. Rubio

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