Digital twin of dynamics for parallel kinematic machine with distributed force/position interaction

Abstract

Extensibility is significant for digital twin (DT) manufacturing systems. However, existing DT models mainly focus on a specific task in manufacturing. The main challenge lies in the specific physical model when addressing different tasks. In fact, the dynamics of machines are the physical basis for most applications, e.g., motion planning, production scheduling, process monitoring, machine maintenance, and so on. Therefore, the Digital Twin of dynamics (DTOD) for machines will be a foundation for a highly integrated and extensible DT system. However, due to the challenges in real-time dynamic modeling and the corresponding data interaction methods, the DTOD for parallel kinematic machines (PKM) has not been realized.

Facing this challenge, this paper develops a DTOD for PKM with distributed force/position interaction. Firstly, a simplified rigid-flexible coupling dynamic model of PKM, considering link deformations, is established for real-time calculation. Then, a distributed position/force interaction method based on Kalman filter-based data fusion is proposed to realize high-performance data interaction between cyber and physical space. On this basis, a five-dimension digital twin model for DTOD of PKM is established. Further, the DTOD system with an architecture comprising dual central processors and multiple distributed edge executors/sensors is developed and validated by aircraft gear manufacturing, showing 80 % prediction accuracy of dynamic error. Finally, to show the extensibility, integrated error correction for aircraft gear manufacturing is proposed as an extended application of the DTOD system. The gear error is reduced to 218 μm (with error correction) from 503 μm, representing a reduction of about 57 %, showing the high performance of the developed DTOD system and its high application potential.