Keeping Digital Twin in Sync Without Blocking the Physical Motion Stage

Digital Twins (DTs) are virtual representations of physical systems or Physical Twins (PTs) that are used for various data-driven applications in manufacturing industry such as predictive maintenance, diagnostics and condition monitoring. The data in DTs is collected through virtual sensors, which augment the physical sensors by providing additional data that cannot be directly observed. In high-throughput production systems like semiconductor manufacturing equipment, highspeed and high-precision motion stages control the equipment's movement. However, the use of DTs in these systems is limited due to their real-time requirements. To enable real-time applications, the DT must be synchronized with its physical counterpart to ensure timely data from virtual sensors. The synchronization mechanism should be non-blocking to prevent any impact on the throughput of physical systems. In this paper, we propose a synchronization mechanism for DTs in high-speed high-precision motion control systems. The mechanism involves sharing PT states with DT over a network and compensating for network delays. The synchronization mechanism is validated in a framework comprising an industrial motion stage system and its digital twin. The validation is done for different synchronization delay scenarios, demonstrating its effectiveness of proposed approach in eliminating synchronization delays without blocking the PT operation. The proposed mechanism enables real-time virtual sensing ensuring data timeliness with high accuracy.