Global output regulation for a class of single input Port-controlled Hamiltonian disturbed systems

The problem of global output regulation for a class of single input Port-controlled Hamiltonian disturbed systems is studied. A composite control method is developed by combining the damping injection and the nonlinear disturbance observer techniques together. A series of coordinate transformation is presented to transform the system with mismatched disturbance into matched disturbance system. By means of Lyapunov stability theorems, global stability analysis for the closed-loop Hamiltonian system is presented. It is shown that the system output is regulated to zero asymptotically in the presence of mismatched disturbance without larger overshoots and longer settling time caused by integral action. Study on two examples with simulation results demonstrates the effectiveness of the proposed control method.