Automatic generation and synthesis of C-frames for mechanical parts in an insertion task

An approach that utilizes the geometric information about the mating parts in generating and synthesizing the C-frame and the compliance-selection vector which are needed at every sampling instant for hybrid position/force control scheme in an insertion task, is presented. A geometric modeling system is used to model the mating objects involved in the insertion task. From the geometric model of the objects and the nominal position-trajectory of the task, a set of cut-planes of the mating objects perpendicular to the insertion direction can be obtained. Due to the uncertainties inherent in working with real-world objects, and the limited position accuracy of the manipulator, an uncertainty model is incorporated into the cut-planes to reflect the position and orientation uncertainties of the C-frame. This approach reduces a difficult three-dimensional problem into a set of two-dimensional problems and will successfully complete the task even in the presence of position and orientation uncertainties. >