A Modified Fuzzy Luenberger Observer for a Two-Mass Drive System

In this paper, issues related to the design of a fuzzy Luenberger observer for a drive system with a flexible joint is presented. The proposed estimator ensures shifting observer closed-loop poles in accordance with the present condition of the plant. The dynamic states are recognized on the basis of the error between the plant and estimator outputs (classical approach), as well as additional signal (difference between electromagnetic, and shaft torque and its derivative). Depending on these signals, the fuzzy systems determine the location of the observer poles. The proposed control structure is investigated through a number of experimental tests.