A design approach of the disturbance observer for the electro-optical tracking system

This paper proposes a new design approach for the disturbance observer (DOB) in the frequency domain. The purpose of the DOB is to realize the plant performing like a model in the presence of disturbances which come from external environment and inherent nonlinearities and uncertainties in the plant. It is shown that the proposed DOB compensates for those disturbances, nonlinearities, and uncertainties of the system, effectively. The internal stability of the DOB is analyzed for a nominal plant and a non-minimum phase plant. Finally, simulation results demonstrate the performance of an electro-optical tracking system by the proposed DOB.