A Novel Attracting-Law based Digital Control Strategy with Improved Convergence Rate and Steady-State Error

In this paper, a novel attracting law with improved convergence rate and steady-state error band is presented for uncertain discrete-time systems, which applies the tracking error itself for the control design. The attracting law is designed based on the monotone increasing continuous function taking its value between 0 and 1 for the absolute value of the tracking error. The disturbance compensation is introduced in the attracting law, by which the controller is designed to ensure faster convergence and better robust stability of the closed-loop system. For characterizing the tracking performance, detailed results of both the absolute attractive layer bound and the steady-state error band are given. The validity of the proposed approach is confirmed by simulation results.