Vision-Enabled Robot-Mill Collaboration for Hybrid Manufacturing

Abstract Recently, convergent manufacturing, or the combination of multiple processes into a single system, has gained attention for potential uses in hybrid additive-subtractive manufacturing. Here, a robot-CNC machine combination is explored as a convergent solution to hybrid manufacturing. Usually, hybrid manufacturing is performed either using a sequential process where parts are moved from additive to subtractive cells or using a process where all operations occur in a single machine. A less explored solution to the hybrid machining problem is to use a combination of two machines operating on the same workpiece to complete the process, allowing for interleaved or simultaneous hybrid processing. In this work, a flexible system is presented where a 6-axis robotic arm for deposition is combined with a 3-axis CNC mill for hybrid manufacturing. With this system, the robot can be moved to and away from the CNC as needed for a flexible manufacturing framework. With the added flexibility of the system, comes the problem of robot localization. Vision based robot localization methods were implemented to address this problem, and studies were conducted to determine the effects of disturbances encountered in a manufacturing environment on the localization performance. Results show that the proposed vision system can locate the robot within .5 mm and .25 deg, causing minimal disruption to the machining process.