Modelling and Specification of Compliant Motions with Two and Three Contact Points

This paper describes the modelling and motion specification of compliant motion tasks with two or three contact points. These tasks cannot be done with Mason's classical "task frame" (TF) or "compliance frame" approach. Hence, a more flexible and versatile motion constraint model is introduced, that maintains most of the intuitiveness of the TF approach. 1 Introduction The literature on force-controlled compliant motion most often uses (implicitly or explicitly) Mason's "Task Frame" (TF) approach, [5], to model the contact situation of the task, to specify the desired motion within this contact model, and to control the task execution. This approach is limited to tasks in which one single orthogonal reference frame suffices to model force-controlled and velocitycontrolled directions of the motion constraint. (See [1] for more details.) Previous publications by the authors (e.g., [3]) have presented extensions to the TF approach that allow to tackle tasks that could not previously be e..