Assessment of the positioning accuracy of a small articulated robot during machining operations

The application of industrial robots for machining of complex parts is a very promising field that refers to the ability of the robot to produce parts with complex geometries that typically requires multi-axes machine tools. However, there are many restrictions that limit the use of robot in advanced manufacturing industry such as positioning errors and low stiffness. This work investigates the positioning accuracy and the path repeatability of a Mitsubishi RV-1A robot with six degree of freedom during machining movements by using a Faro laser tracker. The results obtained show a significant motion error caused by the robot, even with the absence of cutting force. A comparison has been made between the positions of the commanded path measurements taken by the robot controller and the actual position of the end effector of the robot measured by the tracker.