Internal-model-based control to reject an external signal generated by a class of infinite-dimensional systems

In this paper, an internal-model-based controller (IMBC) is designed to reject an external signal generated by a class of infinite-dimensional systems for a class of nonlinear systems. First, a new description of the external signal is proposed. By this new description, the IMBC is designed, and the resulting closed-loop error dynamics are analyzed with the help of a Lyapunov-Krasovskii functional. Compared with existing IMBCs, the designed IMBC provides the flexibility to cope with more types of external signals as well as to choose controller parameters to achieve a tradeoff between rejection performance and stability. Finally, the method is applied to attitude control of a quadrotor aircraft. Effectiveness of the IMBC is demonstrated by simulation.