On the elimination of steady-state errors with an “elastic” fuzzy position controller for motor drives

A new “elastic” fuzzy motor drive position controller is proposed. Fuzzy rules are obtained only with experimental knowledge on motor drive dynamics and then recursively applied to obtain “elastic” non-limited boundaries and the elimination of steady state errors. The “elastic” controller, implemented by a recursive lookup table, performs the “gain” tuning of the fuzzy controller, thus the position control system remains stable for most operating conditions and enables a quasi-robust behaviour when compared with a conventional fuzzy controller. Results are presented using DC and synchronous motors