UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Robotic processes to accelerate large optic fabrication

Wu, H-Y; (2016) Robotic processes to accelerate large optic fabrication. Doctoral thesis , UCL (University College London). Green open access

[thumbnail of 20161114_1_whole thesis_Correction after viva (1).pdf]
20161114_1_whole thesis_Correction after viva (1).pdf

Download (12MB) | Preview


The manufacture of metre-scale optics for the next generation of extremely large telescopes (and many other applications) poses a number of unique challenges. For the primary mirror of the European Extremely Large Telescope, each of its 1.45 m segments will need to be completed with nanometre scale accuracy. This demands an unprecedented combination of hybrid fabricating technology to process nearly 1000 segments before the year 2024. One important aspect in improving the current state-of-the-art manufacturing developments is adding an efficient smoothing process that can achieve a faster, and less expensive, manufacturing process-chain. The current process to finish a prototype segment using CNC grinding and CNC polishing takes approximately 1-2 months, and a significant contributing factor in this is the excessive processing times needed to correct the local grinding marks. In this study, therefore, grolishing, an intermediate process between grinding and polishing, is adopted to smooth the part and reduce the overall manufacturing time. This PhD work serves to advance the development of effective robotic grolishing processes (RGP) by the following achievements: (1) to propose the specification and achieve the requirements; (2) to design tools and establish a mechanism for grolishing; (3) to investigate and propose experimental methods to reduce process times while still achieving high performance, reliability and quality surfaces; (4) to establish the RGP and demonstrate that this process can smooth the errors from grinding and provide superior surfaces for polishing to speed up the current process; (5) to develop prototype metrology systems and algorithms to measure grolished surfaces; and, (6) to investigate an innovative proposed method to control mid-spatial frequencies on complex surfaces by using rotating rigid tools. These novel achievements describe the newest fabrication technology, and anticipate the evolution of the process-chain for future high-quality imaging systems for use in astronomy, space-research and laser physics.

Type: Thesis (Doctoral)
Title: Robotic processes to accelerate large optic fabrication
Event: UCL (University College London)
Open access status: An open access version is available from UCL Discovery
Language: English
Keywords: Grolishing, Segmented telescope, CNC grinding, CNC polishing, E-ELT, TMT, mid-spatial frequencies, DOE, ANOVA
UCL classification: UCL
UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
URI: https://discovery.ucl.ac.uk/id/eprint/1529855
Downloads since deposit
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item