Novel robust disturbance observer

In this paper, a predictive disturbance observer (DOB) design is presented. The proposed DOB does not require a direct model of the process without the transport delay for prediction purposes. The primary advantage of the proposed DOB design is its simplicity due to usage of the prediction block (PB), which approximates the ideal anticipation object. Furthermore, the entire DOB becomes robust to external disturbances because the DOB is based on the approximation of the anticipation object. The response accuracy of the proposed predictive DOB is directly dependent on the inverse model parameters and prediction coefficients in the PB. Notwithstanding the simplification, convenient implementation, identification, and optimization structure, the proposed solution allows for direct implementation of process models describing discontinuous nonlinear time-invariant systems.