Friction: experimental determination, modeling and compensation

The friction behavior of a brush-type-DC-servomotor-driven mechanism with gearing is explored. The standard kinetic plus viscous friction model is found to describe the dominant friction behavior. In addition, a dependence of friction on position is identified and negative velocity dependence is observed at low velocities. A friction model is developed and used to precompute motion torques. The application of a precomputed torques in an open-loop fashion results in motion accurate to within a few percent