Institute of Automation, Qufu Normal University, Qufu 273165,P. R. China;
Institute of Automation, Qufu Normal University, Qufu 273165,P. R. China;
School of Electrical Engineering and Automation,Xuzhou Normal University, Xuzhou 221116, P.R. China;
Discrete-time systems; swapping lemma; L2δ-norm; the normalizing signal; model reference adaptive control;