Friction modelling for robotic applications with planar motion

摘要

Friction is a topic that has been researched since the times of Leonardo da Vinci.The computation of friction allows to derive the force which is needed in order to set robotic devices in motion.To be able to do this, different friction models have been developed.Among these are models that directly connect the velocity to the frictional force such as Coulomb friction and viscous friction, as well as models that use an extended state, for example the model by Dahl, the LuGre model and the elasto-plastic model.However, all these friction models have in common that they only focus on one-dimensional motion.However in many robotic manipulation applications the objects move on a plane e.g. when an object can move in the robotic gripper depending on the grasping force.One-dimensional models cannot capture these multi-dimensional motions like sliding and spinning.Therefore it is necessary to model friction not only for a one-dimensional motion but also for planar motion.There are models that combine translational and rotational friction, but only the Coulomb friction model has been taken into account.Thus in this thesis the combination of different friction models and planar motion is examined.To achieve this the computation of the states of the more refined friction models were changed to include constraints that arise for multi-dimensional friction modelling.These constraints allow the coupling of translational and rotational motion as the frictional forces for both motions are interacting.v vi