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Controllability of Fractional Chapter | 8  231


                                                ð  t
                q
              C D xðtÞ AA D xðtÞ1 BuðtÞ 1 Fðt;xðtÞÞ1  Gðs;xðsÞÞdwðsÞ;  tA 0;TŠ : 5 J;
                           p
                        C
                                                                   ½
                                                 0
                                                  0
                                         xð0Þ 5 x 0 ; x ð0Þ 5 x 0
                                                        0
                                                                        ð8:1Þ
             where  C D q  and  C D p  denote Caputo fractional derivatives of order
             0 , p # 1 , q # 2; A and B are matrices of dimensions n 3 n and n 3 m ,
                            n
                                  m
             respectively, xAR ; uAR are the state and control vectors. The nonlinear
             functions f; G are appropriate functions to be defined later.
                The chapter is organized as follows: In Section 8.2, some essential results
             on the basic definitions of fractional integral and derivatives, Lemmas, pro-
             positions, and some hypotheses are given to obtain the controllability results
             successfully. In Section 8.3, the controllability results for the fractional sys-
             tem (8.1) are studied under the fixed point theorems. In Section 8.4, a discus-
             sion and future work is given. Finally, conclusions are drawn in Section 8.5.
                Notations: Throughout this chapter, ðΩ; F; PÞ denotes the complete prob-
             ability space with a right continuous and complete filtration fF ; tAJg (F t
                                                                   t
                                                           n          o
                                                              H
             the σ 2 algebra generated by the random variables  W ; sA½0; tŠ  and
                                                              ðsÞ
                                                       n
             P 2 null set) and satisfying F CF: Let L 2 ðΩ; F ; R Þ be the Hilbert space of
                                     t
                                                    T
                                                                           n
             all F 2 measurable square-integrable random variables with values in R :
                 T
                 F    n
             Let L ðJ; R Þ be the Hilbert space of all square integrable and F 2 measur-
                 2                                                t
                                                       n
                                         n
             able processes with values in R : Let B 5 CðJ; R Þ be the Banach space.
                               n
             Denote the class of R 2 valued stochastic processes fξðtÞ:tAJg which are
             F 2 adapted and have a finite second moments, i.e.,
              t
                                                   1

                                                2 2
                                 :ξ: 5 sup EjξðtÞj  , N:
                                        t
                For convenience, define the following notations
                                   2                              2
               n 1 5 sup:E q2p ðAt q2p Þx 0 : ; n 2 5 sup:At q2p E q2p;q2p11 ðAt q2p Þx 0 : ;
                                                              2
                                     2
                                                                      21 2
               n 3 5 sup:tE q2p;2 ðAt q2p Þx : ; n 4 5 sup:E q2p;q ðAðt2sÞ q2p Þ: ; l 5 :W : :
                                   0
                                   0
             8.2  PRELIMINARIES
             Let R n  be the n-dimensional Euclidean space, R 1 5 ð0; NÞ; f ðtÞ be a
             suitable function and the fractional order q . 0; with n 2 1 , q # n; nAℕ:
             Then the following results are well known (for more details, see Miller and
             Ross, 1993; Oldham and Spanier, 1974; Samko et al., 1993; Sabatier et al.,
             2007; Kilbas et al., 2006; Kexue and Jigen, 2011).
                Caputo fractional derivative is defined by
                                   C
                                      q
                                                  n
                                  ð D fÞðtÞ 5 ðI n2q D fÞðtÞ;
                                              01
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