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Page 305                        Peng et al. Intell Robot 2022;2(3):298­312  I http://dx.doi.org/10.20517/ir.2022.27

                                                                                           
                                                                                      2  Í    
                                                                                     k +      (   0 )            (   0 ) for
               Clearly, there exists the maximum of |  (  )| for    ∈ [   0 −       ,    0 ]. Thus,   (   0 ) ≤   k      0       
                                                                                           =1
               some    > 0.
               Therefore, the exponential stability of the system Equation (12) with   (  ) = 0 is guaranteed.

               Next, we will show that


                                                                       holds for any nonzero    ∈    2 [0, +∞).
               (ii) under the zero initial condition, the inequality k  k    2  ≤   k  k    2
               From Equation (19), we obtain that for    ∈ [      ,      +1 ),

                                                                            
                                                        p             1  Õ    p
                                 2   2     2    ¤                 2                    2              (27)
                                                                (  )| +
                             |  (  )| −    |  (  )| ≤ −  (  ) + 2  |                 |                   (  )| .
                                                                          
                                                                          =1,  ≠     
               Integrating Equation (27) on    from       to    −  yields
                                                    +1
                                 ¹      −
                                      +1   2    2     2
                                       |  (  )| −    |  (  )|      +   (     +1 ) ≤   (      ) + Θ    ≤   (      ).  (28)
                                       
               Then, by summing Equation (28) on    from 0 to   , where    → +∞, we have
                                           ¹     −
                                               +1    2   2     2
                                                (|  (  )| −    |  (  )| )     ≤   (   0 ).            (29)
                                               0
                                            ¯                ¯
                                                   
                                                                       
               Under the zero initial condition,  +∞     (  )  (  )     ≤  +∞       (  )  (  )    . Therefore, one can derive that
                                                                   2
                                            0                 0
                                                         for any nonzero    ∈    2 [0, +∞). This completes the proof.
               under the zero initial condition, k  k    2  ≤   k  k    2
               □
               Remark 2 The feasibility of the linear martix inequalities has been sufficiently explained in [23,28] . Due to page
               limitations, this part is omitted here.
               3.2. Stability analysis under the RR scheduling scheme Eqution (7)
               Construct the following Lyapunov-Krasovskii functional candidate:
                                        (  ) = Π(  ) +       +       ,    ≥    − 1,    ∈ [      ,      +1 ),  (30)

               where

                                          −1  ¯        √
                                         Í        
                                                      2  (  −  )  |             ¤  (  )    ,    ≠    − 1,
                                        
                                            =1       
                                         =
                                           −1
                                         Í    ¯        √
                                                    2  (  −  ) |             ¤  (  )    ,    =    − 1,
                                                
                                                  0
                                           =1
                                                                −1
                                                              Õ        +1 −     q
                                                                                     2
                                                                                
                                         = (   − 1)         2  (  −1)      ,      =  |         −         −    (  )| .
                                                                          
                                                                =1
               Similar to Theorem 5.2 in [29] , we establish the following result.
               Theorem 2 Under RR scheduling scheme Equation (7), given       > 0 and    > 0, assume that there exist matrices
                  > 0,    > 0,   > 0,       > 0,    = 1, · · · ,    and    with appropriate dimensions such that Equation (15) and
               Equation (16) are feasible with       =         , where       is given by Equation (30). Then, system Equation (12) is
                                                −1
               exponentially stable with a prescribed    ∞ performance   .
               Proof: The detailed derivation process can refer to [29]  and the proof of Theorem 1, which is omitted here due
               to the limited pages.                                                                    □
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