Observer-based optimal/sub-optimal digital trackers for analog neutral systems with multiple discrete and distributed time delays

In this paper, observer-based finite/infinite time optimal hybrid tracking problems for analog neutral systems with multiple discrete and distributed time delays are formatted and studied. Two continuous-time optimal performance indices with a highgain property are used for tracking control specification. The Newton center interpolation formula and the linear interpolation formula, together with a newly modified rectangular ruler and an extended state vector, are utilized to construct the associate problems of extended discrete-time finite/infinite stage optimal regulators. Consequently, using the discrete-time optimal control theory and the new alternative digital redesign technique with a predictive feature, three effective digital trackers are designed for a given analog neutral system. When the states of the system are not available, a new optimal digital observer for the original analog neutral system is developed for achieving the desired goals of tracker design.