Procedures and Performance of a Robotic Machining System with Metrology-in-the-loop Feedback Control

In recent years, the use of industrial robots in advanced manufacturing applications has become increasingly popular. With larger workspaces and lower costs relative to more traditional machine tools, the use of robots has significant upsides in machining applications. However, due to their relatively low accuracy, the use of industrial robots in these applications is limited. One way to improve robot accuracy is to provide feedback control via external sensors such as laser trackers. This paper presents several techniques used to identify key parameters for a laser tracker controlled robotic machining system. Specifically, transformations between the coordinate frames within the system are crucial to its performance since error in these parameters are generally not observable by the feedback system. The identification methods are used to perform full-scale machining experiments. These experiments demonstrate the improved machining performance of the laser tracker controlled robotic machining system when compared to the machining performance without feedback control.