Force Controlled Robotic Surface Finishing with Variable Tool Centre Point (TCP)

Industrial robots equipped with cutting or abrasive tools are becoming increasingly important for manufacturing operations that require material removal. In these operations, the robot creates physical interaction between the tool and the workpiece by sequentially positioning the tool centre point (TCP) at the poses on the toolpath. The effect of the TCP definition on the process outcome may easily be unnoticed since it is generally seen as a trivial parameter to be set once for the entire operation. However, depending on the tool and the workpiece geometries, using a constant TCP may not yield the anticipated contacts. In this paper, we investigate the use of multiple TCPs and propose two novel methods that can change the TCP on the fly based on the surface normals of a workpiece or user input. The proposed methods have the potential to improve the efficiency and quality of force-controlled surface finishing operations performed by industrial robots.