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Multiswitching Synchronization Chapter | 15  461


                This function results in control functions given by Eq. (15.25) to give
             multiswitching synchronization with switch 3.

             15.4.4 Case 4

             For Switch 4 defined by Eq. (15.14), the time derivative of the errors is
             given by
                  q
                 d e 41
                     5 y 2 2 x 3 1 u 1 ðtÞ
                  dt q
                     5 e 42 1 u 1 ðtÞ
                  q
                 d e 42     3                                          3
                     5 y 1 2 y 2 αy 2 1 fcosωt 1 u 2 ðtÞ 1 β x 1 1 β x 2 1 β x 3 2 β x
                                                                3
                                                          2
                                                    1
                            1
                                                                      4 1
                  dt q
                     5 e 41 2 αe 42 2 f 41 ðx; yÞ 1 u 2
             where f 41 are nonliear terms in e 11 and e 12 given as
                                   3
                     f 41 5 x 2 2 αx 3 2 y 1 fcosωt 1 β x 1 1 β x 2 1 β x 3 2 β x 3
                                                           3
                                               1
                                                     2
                                                                 4 1
                                   1
             Theorem 4: If the control function u 1 ðtÞ and u 2 ðtÞ are chosen such that
                             u 1 ðtÞ 5 k 1 e 41 1 e 42
                                                                      ð15:29Þ
                             u 2 ðtÞ 52 f 41 ðx; yÞ 1 e 41 1 ðk 2 2 αÞe 42
             then the drive system 15.9 will achieve multiswitching synchronization with
             the response system 15.10
             Proof: We redefine u 1 ðtÞ and u 2 ðtÞ to eliminate all the nonlinear terms in
             e 41 and e 42

                                  u 1 ðtÞ 5 V 41 ðtÞ
                                  u 2 ðtÞ 52 f 41 ðx; yÞ 1 V 42 ðtÞ

                                     V 41 ðtÞ    e 41
                                            5 D
                                     V 42 ðtÞ    e 42
             where D is a 2 3 2 constant matrix. In order to make the closed-loop system
             stable, the matrix A should be chosen such that the eigenvalues λ i of D
             satisfies
                                jargðλ i Þj . 0:5πα; i 5 1; 2; ...:
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