Global Robust Finite Time Control for A Class of Uncertain Second-order Nonlinear Systems

For the tracking control of a class of uncertain second order nonlinear systems, this paper proposes a robust global finite time control strategy. This control strategy consists of two parts: firstly, a time-varying sliding mode controller is designed to make the tracking errors to zero at a desired finite time t(r); then, in the succeeding time t> t(r), another nonsingular terminal sliding mode controller is used to make the tracking errors stay at zero. The algorithm has the following advantages: 1) the tracking error convergence time can be set in advance; 2) error convergence rate can be adjusted by changing the value of a parameter; 3) global robustness is guaranteed for parameter uncertainty and external disturbance. Numerical results demonstrate the usefulness of the proposed control strategy.