A digital twin is the virtual representation of a system (such as a CNC machine tool and the machining process). In the case of a CNC machine, this simulated system mirrors the real CNC machine tool in detail, including accurate characterization of the machine kinematics, structural dynamics, motion control settings, etc. The NC program generated from CAM software can then be examined under such a virtual machine, thereby realizing a digital twin which simulates the manufacturing process.
The implementation of a digital twin has numerous applications that improve the quality, productivity and monitoring of machining operations. For machining optimization, a digital twin is applied in lieu of a real machining operation to examine the process states (force, torque, power, vibrations, etc.). Such simulation can reveal problematic NC programs and allows automatic optimization of the process. In-process monitoring, the digital twin can be implemented online in synchronization with the CNC inherent data and external sensor data. The comparison of digital twin and real data leads to a diagnosis of tool failures, tool wear, tool-spindle overload locations, chatter frequency and location which helps the planner to learn from the machine and improve the process.
