Digital twin-driven ultra-precision machining system

Ultra-precision machining technology is at the forefront of manufacturing technologies which enables development of scientific instruments (e.g. particle colliders, gravitational-wave interferometers, space, or ground-based telescopes) for big science discovery and underpins technological advancement in microelectronics, information technology, photonics, and quantum sectors. It heavily replies on ultra-precision machining system which exhibits high degrees of thermal stability, stiffness, damping, and high precision motion motional stage to obtain high-precision products with a ratio of product tolerance to its dimension of less than 1 part in 10-6. Nowadays, ultra-precision machining industry stands on the threshold of a technological revolution and a digital transformation that is considered a key driver for improved productivity and further enhanced machining precision.

This talk will firstly discuss evolution of ultra-precision machining system and industrial automation technology for obtaining high-end plano, spherical/aspherical and freeform components. It will then introduce the concept of emerging digital twin (DT) technology in the new era of Industry 4.0. It will also review current research by applying DT for system design, process planning, modelling and optimisation, and quality assurance and maintenance. A case study on development of a predictive DT-driven ultra-precision machining system for dynamic error control will be present for accuracy control in high-frequency slow-tool-servo ultraprecision diamond turning processes. The effectiveness of the DT-driven ultra-precision machining system was demonstrated through machining trials which showed significant improvement in machining accuracy (87%, surface form accuracy; 95%, phase accuracy with precisions of 0.06 µm and 0.05°), and efficiency (8 times the state-of-the-art).