Adaptive Practical Output Tracking Control for High-order Nonlinear Uncertain Systems

The problem of adaptive practical output tracking control is studied for a class of high-order nonlinear uncertain systems, which has been investigated under the assumption that the lower bounds of the unknown control coefficients are exactly known. Based on the idea of the new robust adaptive control and the continuous stabilization, this assumption is successfully removed. By means of adding a power integrator, a systematic approach is developed to construct a continuous adaptive practical output tracking controller, which guarantees that all the states of the closed-loop system are globally stable, while the tracking error can be bounded by any given positive number after a finite time. Finally, a simulation example is given to illustrate the correctness of the theoretical results.