Advanced methods for small batch robotic machining of hard materials

Abstract

The research presented in this paper focuses on automatic machining of hard materials using standard industrial robots. The automation of robotic milling utilizes CAD/CAM, robotic planning tools and advanced robot control algorithms. In order to achieve high milling accuracy, the generated milling paths by CAM program have been optimized by means of a novel robotic milling toolbox. These tools take into consideration robot specific performance and constraints to optimize robotic milling before generating automatically executable program for the robot controllers. To cope with nonlinear effects of robot joint friction, path governor function has been developed, to regulate in real time the velocity in the case of increasing errors. The problems of grinding and polishing have been addressed using robust impedance and force control. The presented experimental results of robotic stone and metal machining illustrate high achievable performance and complete parts machining using conventional industrial robots.