Programming a damping matrix for error-corrective assembly

During a robotic assembly operation small errors of position and orientation of contacting parts are inevitable. The errors result in characteristic contact forces which, as a function of the manipulator's compliance, lead to small deviations of the manipulator from its nominal trajectory. The deviations may serve to increase or to decrease the errors. Thus the evolution of a robotic operation toward increasing or decreasing errors is intimately involved with the compliance of the manipulator. In this paper, an attempt is made to automate the synthesis of a user-selectable error corrective damping matrix for a given task, i.e., a six-by-six matrix which maps forces and torques into translational and rotational velocities.