Adaptive minimum variance control

of separately excited DC motor


Z. Zidane*,  M. Ait Lafkih, M. Ramzi

Laboratory of Automatic and Energy Conversion (LAEC)

 Electrical Engineering Department, Faculty of Sciences and Technology, University of Sultan Moulay Slimane, B.P: 523,

23000 Beni-Mellal, Morocco

* Corresponding author: E-mail:

Received: 10 November 2010; revised version accepted: 04 May 2011



            In this paper, the Adaptive Minimum Variance Control is designed to minimize a variance of a speed of separately excited DC motor. The model of the process has been obtained by using on-line identification technique to obtain a model for the dynamic behaviour between the armature voltage input and the speed of a DC motor. The Minimum Variance Control for Single-Input Single-Output (SISO) systems described by linear vector difference equations with constant but unknown parameters is presented. A Single-Input Single-Output self-tuning regulator based on Minimum Variance is then proposed. It uses a Recursive Least Squares (RLS) estimator and a linear controller obtained directly from the current estimates. The Adaptive Minimum Variance Control is then applied to minimize the variance of the output of the plant. The performance of the proposed controller is illustrated by a simulation example of separately excited DC motor. Obtained results demonstrate the effectiveness and superiority of the proposed algorithm.


Keywords: Separately Excited DC Motor; Minimum Variance; Self-Tuning regulator; Parameter estimator; Identification; RLS method.

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