Optimal auto-tuning of fractional order PIλ Dμ controller for a DC motor speed using Extremum seeking

Fractional calculus provides novel and higher performance extensions for fractional order proportional integral and derivative (FOPID) controller. In this paper, the parameters of the FO PI^λ D^μ controller are optimally learned by using Extremum Seeking (ES) approach, and the optimization performance target is chosen as the integral of square error (ISE). ES is a non-model based method which searches on-line for the parameters that minimize a cost function; in this case the cost function is representative of the controller´s performance. Furthermore, this method has the advantage that it can be applied to a plant in which there is no knowledge of the model. The FOPID parameters are tuned based on the results of step response simulations to produce a response with minimal settling time and overshoot. Comparative simulation results on a DC Motor speed control show the effectiveness of the proposed strategy for fractional order PI^λ D^μ tuning.