Output feedback regulation of large-scale feedforward systems with discrete and distributed delays

This paper proposes an output feedback control strategy to achieve the global regulation of a class of large-scale feedforward nonlinear systems with discrete and distributed delays. The nonlinear terms are assumed to be bounded by the continuous functions of inputs multiplied by an unknown constant, and the discrete and distributed delays are allowed in the inputs and states. A novel design approach, namely dynamic gain construct method, is given to design the observers and the output feedback controllers. On the basis of the Lyapunov-Razumikhin theory, the global regulation of the closed-loop system is proved. Different from the existing results, a dynamic gain is online updated by the systems outputs and the observers states. Moreover, the time-varying gain with the logarithmic form is first constructed under a unified framework, which is also a valid control algorithm in coping with the uncertainty of the concerned systems. A simulation example is provided to demonstrate the effectiveness of the theoretic results.