Output feedback control for a class of nonlinear time delay systems with prescribed performance

This paper studies the problem of output feedback control for a class of nonlinear time delay systems with prescribed performance. The system is in the form of triangular structure with unmodeled dynamics. First, we introduce a reduced-order observer to provide the estimate of the unmeasured states. Then, by setting a new condition with the performance function, we design the state transformation with prescribed performance control. By employing the idea of the backstepping method, we construct the output feedback controller. It is proved that the resulting closed-loop system is asymptotically stable and both transient and steady-state performance of the output are preserved with the changing supplying function idea. Finally, a simulations example is conducted to show the effectiveness of the main results.