An Online Observer for Minimization of Pulsating Torque in SMPM Motors

<div><p>A persistent problem of surface mounted permanent magnet (SMPM) motors is the non-uniformity of the developed torque. Either the motor design or the motor control needs to be improved in order to minimize the periodic disturbances. This paper proposes a new control technique for reducing periodic disturbances in permanent magnet (PM) electro-mechanical actuators, by advancing a new observer/estimator paradigm. A recursive estimation algorithm is implemented for online control. The compensating signal is identified and added as feedback to the control signal of the servo motor. Compensation is evaluated for different values of the input signal, to show robustness of the proposed method.</p></div

Online parameters estimation graphs for one filtered harmonic.

<p>Online parameters estimation graphs for one filtered harmonic.</p

Compensation of a 7V excitation signal with load.

<p>Compensation of a 7V excitation signal with load.</p

Parameters estimation graph for entire set of harmonics for 6V.

<p>Parameters estimation graph for entire set of harmonics for 6V.</p

Normalized distribution of harmonics.

<p>Normalized distribution of harmonics.</p

Frequency spectrum for u = 6V (a) and u = 14V (b).

<p>Frequency spectrum for u = 6V (a) and u = 14V (b).</p

Compensation of a 7V excitation signal with no load.

<p>Compensation of a 7V excitation signal with no load.</p

System overview and experimental test bed.

<p>System overview and experimental test bed.</p

Filter output for u = 4V, 4.5V and 5V.

<p>Filter output for u = 4V, 4.5V and 5V.</p