Output feedback control for interconnected time-delay systems with prescribed performance

This paper studies the problem of output feedback control for interconnected time-delay systems with prescribed performance. Currently, few of the existing results consider the prescribed performance control in the nonlinear interconnected time-delay systems. The subsystems are in the form of triangular structure with unmodeled dynamics. First, we design a reduced-order observer to estimate the unmeasured states online instead of the traditional full-order observer. Then, by proposing a new state transformation with the performance function, we construct a novel output feedback controller with the idea of the backstepping method. It is strictly proved that the resulting closed-loop system is stable in the sense of uniformly ultimately boundedness and both transient and steady-state performances of the outputs are preserved. Finally, a simulation example is given and the results show the effectiveness of the proposed control design method.