Velocity tracking control for a separately excited DC motor without velocity measurements

This paper applies advanced control techniques to the problem of sensorless velocity control for wound stator DC electric motors. Specifically, a nonlinear observer and a nonlinear integrator backstepping controller are developed for the separately excited wound stator motor configuration. The proposed controller, when used with the corresponding velocity observer, is shown to produce exponentially stable velocity tracking using only current measurements. The controller is based on a mathematical model of the electric motor which includes saturation in the stator magnetic circuit. Experimental results are provided to verify velocity tracking performance of the proposed control system.