Passivity-based observer/controller design with desired dynamics compensation for 6 dofs parallel manipulators

This article provides a tracking scheme for 6 DOFpsilas parallel robots. It is based on a controller/observer combination with an additional compensation of the desired dynamics. The latter is necessary to avoid an online calculation of the direct kinematics. However, it introduces systematic errors. To take such deviations into account a passivity based formalism is used. The resulting approach is experimentally substantiated and proven to be highly powerful and robust against initial errors and model uncertainties.