The Use of Compliance and Constraint for Improved Robotic Material Removal Processes

In this paper, a method for accurate positioning using compliance and constraint is applied to material removal processes. Accurate force guidance is achieved through the use of an end-effector mounted jig in conjunction with the proper design of the compliance of the manipulator and the material removal tool. The compliance of the manipulator is designed so that: 1) an initial unique relative position/orientation of the jig with respect to the workpart edge is attained despite manipulator positioning error; and 2) the unique relative position initially established is maintained while moving along the workpart edge. Also, the stiffness of the material removal tool is regulated to ensure that forces associated with material removal do not degrade the accuracy of jig-assisted force guided manipulator positioning. This work has application in material removal processes in which accurate positioning with respect to an edge is important, e.g., robotic deburring and aircraft panel drilling. Conditions on the manipulator compliance also have application in robotic assembly