Global stabilization of feedforward nonlinear time-delay systems by bounded controls

The problem of global stabilization for a family of feedforward nonlinear time-delay systems by bounded controls is considered. Based on a special canonical form of the considered nonlinear system, two types of new nonlinear control laws are proposed to achieve global stabilization. The new special canonical form used in this paper contains not only time delay in the input but also time delays in the state, which leads to natural cancellation in the recursive design. Moreover, some free parameters are introduced into these controllers. These advantages can help to simplify the proof for the global stability of the closed-loop system and improve the transient performance of the closed-loop system significantly. A practical example is given to illustrate the effectiveness of the proposed approaches.