Active Compensation of Friction in Electric Power Steering

The basic concept of the so-called MS mimic control strategy is developed and applied to a column assist electric power steering (C-EPS) in this paper. In this strategy, the friction of the assist column only is compensated assuming that the friction effects can be lumped into a single equivalent friction model and that its parameters are known and constant. The friction of the rack-pinion gear remains as in a manual steering system (MS). This strategy is of interest as the significant friction of the worm gear is compensated with the available sensors and actuators. This study addresses the potentials of an active compensation that could be generalized to the rack and pinion gear.