ROBUST CONTROL OF A CLASS OF NONLINEAR SYSTEM WITH TIME-VARYING PARAMETRIC UNCERTAINTIES

摘要

A class of triangular nonlinear system with disturbances which has unknown multiplicative time-varying parametric uncertainties in each virtual control is treated by a backstepping technique. The controller designed for all admissible uncertainties can guarantee that all states of its closed-loop system are uniformly bounded. The robust controller design algorithm and a sufficient condition of the system stability are given. In addition, the closed-loop system has an ISS property when the multiplicative time-varying parametric uncertainties are viewed as inputs to the system. Thus, this design provides a way to prevent a destabilizing effect of the multiplicative time-varying parametric uncertainties. Finally, simulational example is given and simulational result shows that the controller exhibits effectiveness and excellent robustness.