Sensorless speed measurement using current harmonic spectral estimation in a DC-motor

In the motor control industry, DSP systems offer major improvements over analog designs, enabling notably to replace speed or position sensors by the implementation of sensorless control algorithms. In this paper, we propose a new viable method which estimates the rotor velocity of a permanent magnet DC-motor from the "rotor slot harmonics" present in the DC current signal. This approach is based on both two adjustable digital filters and a frequency estimator, which is fitted to this particular application and compared to a classical technique