About fractional models physical consistency: Case of implicit differentiation based fractional order models

As recently shown, a fractional model can be viewed as a doubly infinite model: its “real state” is of infinite dimension as it is distributed, but it is distributed on an infinite domain. It is shown in the paper, that this last feature induces a physically inconsistent property: the model real state has the ability to store an infinite amount of energy. This property demonstration is based on an electrical interpretation of fractional models. As a consequence, even if fractional models permit to capture accurately the input-output dynamical behavior of many physical systems, such a property highlights a physical inconsistence of fractional models: they do not reflect the reality of macroscopic physical systems in terms of energy storage ability. This property is shown for implicit fractional models and extends previous result of the authors for explicit fractional models.

[1]  Igor Podlubny,et al.  Geometric and Physical Interpretation of Fractional Integration and Fractional Differentiation , 2001, math/0110241.

[2]  A. Oustaloup Systèmes asservis linéaires d'ordre fractionnaire : théorie et pratique , 1983 .

[3]  O. Marichev,et al.  Fractional Integrals and Derivatives: Theory and Applications , 1993 .

[4]  Raoul R. Nigmatullin,et al.  Fractional integral and its physical interpretation , 1992 .

[5]  Carl F. Lorenzo,et al.  Equivalence of History-Function Based and Infinite-Dimensional-State Initializations for Fractional-Order Operators , 2013 .

[6]  O. Agrawal,et al.  Advances in Fractional Calculus: Theoretical Developments and Applications in Physics and Engineering , 2007 .

[7]  D. Matignon Stability properties for generalized fractional differential systems , 1998 .

[8]  Carl F. Lorenzo,et al.  Initialization in fractional order systems , 2001, 2001 European Control Conference (ECC).

[9]  Raoul R. Nigmatullin,et al.  Section 10. Dielectric methods, theory and simulation Is there geometrical/physical meaning of the fractional integral with complex exponent? , 2005 .

[10]  R. Rutman,et al.  On physical interpretations of fractional integration and differentiation , 1995 .

[11]  Manuel Duarte Ortigueira,et al.  The Incremental Ratio Based Causal fractional Calculus , 2012, Int. J. Bifurc. Chaos.

[12]  Carl F. Lorenzo,et al.  Energy Storage and Loss in Fractional-Order Systems , 2015 .

[13]  Alain Oustaloup,et al.  On a representation of fractional order systems: interests for the Initial Condition Problem , 2008 .

[14]  Jean-Claude Trigeassou,et al.  Initial conditions and initialization of linear fractional differential equations , 2011, Signal Process..

[15]  Alain Oustaloup,et al.  How to impose physically coherent initial conditions to a fractional system , 2010 .

[16]  Carl F. Lorenzo,et al.  Initialization of Fractional Differential Equations: Theory and Application , 2007 .

[17]  Alain Oustaloup,et al.  A Lyapunov approach to the stability of fractional differential equations , 2009, Signal Process..

[18]  Christophe Farges,et al.  Analysis of fractional models physical consistency , 2017 .

[19]  J. Sabatier,et al.  From partial differential equations of propagative recursive systems to non integer differentiation , 1999 .

[20]  YangQuan Chen,et al.  Fractional-order Systems and Controls , 2010 .

[21]  Alain Oustaloup,et al.  Fractional Order Differentiation and Robust Control Design , 2015 .

[22]  Horst R. Beyer,et al.  Definition of physically consistent damping laws with fractional derivatives , 1995 .

[23]  Xavier Moreau,et al.  Fractional behaviour of partial differential equations whose coefficients are exponential functions of the space variable , 2013 .

[24]  O. Agrawal,et al.  Advances in Fractional Calculus , 2007 .

[25]  Christophe Farges,et al.  On Observability and Pseudo State Estimation of Fractional Order Systems , 2012, Eur. J. Control.

[26]  Christophe Farges,et al.  Fractional systems state space description: some wrong ideas and proposed solutions , 2014 .

[27]  A. Oustaloup La dérivation non entière , 1995 .