Observer design for an electromagnetically actuated dry clutch

A friction clutch equipped with an electromagnetic actuator is considered. The goal is to estimate the air gap between an electromagnet and an armature, which allows to compress the clutch discs. Starting point is the design of an observer by linearization along a trajectory. In order to improve the estimation, a sliding mode observer using super twisting concepts is developed in this paper. By means of a sensitivity analysis it is shown that the developed sliding mode observer is capable to estimate the position under the presence of parameter variations.