An estimation technique of three elements in closed loop system

In this paper is considered an estimation technique of model of sub-systems in closed loop system using extended least squares algorithm. The closed loop configuration system is very common in practical situation such as in industries. There are three sub-systems of the closed loop system to be estimated simultaneously: feedback, feedforward, and noise. It has been assumed that the system considered was linear and time invariant. The technique uses two estimators algorithm in parallel. The analysis shows that the proposed technique is unbiased. The estimator´s algorithm may be implemented in batch or recursively to estimate simultaneously the three sub-systems in the closed loop system. The simulation shows perfect result of the estimated model for feedforward component, while the estimated feedback and the estimated noise, had larger gain than the original. Furthermore, the technique provides perfect result of the estimated model of closed loop sensitivity between the input of the closed loop system and the input of the feedforward component.