An Application of the Extended Kalman Filter for a Sensorless Stepper Motor Drive Working With Long Cables

In this paper, an approach is proposed for the application of an extended Kalman filter (EKF) to a sensorless stepper motor drive, when the motor is separated from its drive by long cables. When the long cables and high-frequency pulsewidth-modulated control voltage signals are used together, the electrical signals differ greatly between the motor and drive sides of the cable. Since we consider the case where only drive-side data are available, it is therefore necessary to estimate the motor-side signals. Modeling the entire cable and motor system in an EKF is too computationally intensive for standard embedded real-time platforms. It is, therefore, proposed to divide the problem into an EKF, based only on the motor model, and separate motor-side signal estimators, the combination of which is less computationally demanding. The proposed approach´s effectiveness is demonstrated in simulation.