Sensor-less estimation of frictions and moment of inertia of a stepper motor in a machining device

Stepper motor are widely used for both, industrial and commercial applications because of their low cost, high reliability and high torque. The knowledge of mechanical parameters like load inertia and frictions are required in order to parametrize correctly the motor controller. Estimation of these parameters is possible with position sensors but they are expensive in comparison to the motor, furthermore it may not be possible the installation because of unavailability of space. Current sensors are supposed available.