A Compliance Control Approach for Machining Tasks Using Elastic Joint Manipulators

In this paper is presented the development of an indirect force control for robot manipulators with elastic joints employed in machining tasks. Based on the study of centralized compliance control for rigid manipulators, it is proposed an extension for robots with torsional flexibility in the joints structured as a cascade control. Additionally, it is proposed a reduced force model, based on existing dynamic models of the reaction forces, that agree with the reaction forces generated by the cutting tool in contact with the environment. The present two-dimensional model relies on the tangential and normal forces on the surface, allowing to analyze the stability of the system and to obtain gain preconditions for the proposed controller, considering the parameters of the machining process. A machining task is specified and simulation results for this task are presented to analyze the effectiveness of the proposed controller.