Advertisement

Form error compensation in the slow tool servo machining of freeform optics

  • Vinod Mishra
  • Dali R. Burada
  • Kamal K. Pant
  • Vinod Karar
  • Sunil Jha
  • Gufran S. KhanEmail author
ORIGINAL ARTICLE
  • 210 Downloads

Abstract

Advancements in diamond turning technology with tool servo configurations enables the generation of precise freeform surfaces. However, the profile accuracy is mainly limited due to non-availability of an efficient tool path compensation techniques and precise alignment methods. The aim of this study is focused on developing a tool path compensation routine for slow tool servo machining of freeform optics. A seven-order polynomial freeform surface, designed for hyperspectral imaging is selected for experimentation. Alignment strategy by utilizing the available fiducials is presented to ensure the precise re-mounting of surface during machining and metrology. The contact type profilometer is used to measure the fabricated surface by taking 25 numbers of two-dimensional raster scans at an interval of 0.5 mm. The scans are then stitched to get the 3D surface measurement. The residual form error map is used to compensate the tool path. Significant reduction in form error, i.e., from peak to valley (PV) of 9.27 to 0.75 μm with surface finish (Ra) of 11.82 nm, is achieved by performing four machining iterations of compensation. The simulation studies are also presented to investigate the effects of various misalignments on manufacturing accuracies. The developed compensation process is effective for fast convergence of form error and to manufacture the precise freeform optics for various imaging and non-imaging applications.

Keywords

Freeform optics Slow tool servo Ultra-precision machining Fiducial alignment Form error compensation 

Notes

Acknowledgements

We acknowledge Prof. Stefan Sinzinger of Technical University, Ilmenau, Germany, for providing the design data of the freeform surface for fabrication experiment under Indo-German DSTDAAD Project-Based Personnel Exchange Program 2013 to 2015

References

  1. 1.
    Abd El-Maksoud RH, Hillenbrand M, Sinzinger S (2013) Parabasal theory for plane-symmetric systems including freeform surfaces. Opt Eng 53(3):031303–031303.  https://doi.org/10.1117/1.oe.53.3.031303 CrossRefGoogle Scholar
  2. 2.
    Zhang X, Zheng L, He X, Wang L, Zhang F, Yu S, Shi G, Zhang B, Liu Q, Wang T (2012) Design and fabrication of imaging optical systems with freeform surfaces. Proc SPIE Int Soc Opt Eng 8486:848607–848610.  https://doi.org/10.1117/12.928387 CrossRefGoogle Scholar
  3. 3.
    Zhenrong Z, Xiang H, Xu L (2009) Freeform surface lens for LED uniform illumination. Appl Opt 48(35):6627–6634.  https://doi.org/10.1364/ao.48.006627 CrossRefGoogle Scholar
  4. 4.
    Clayor N, Combs DM, Lechuga OM, Mader JJ, Udayasankaran J (2004) An overview of freeform optics production. In: Proceedings of the SPIEGoogle Scholar
  5. 5.
    Fang FZ, Zhang XD, Weckenmann A, Zhang GX, Evans C (2013) Manufacturing and measurement of freeform optics. CIRP Ann Manuf Technol 62(2):823–846.  https://doi.org/10.1016/j.cirp.2013.05.003 CrossRefGoogle Scholar
  6. 6.
    Lasemi A, Xue D, Gu P (2010) Recent development in CNC machining of freeform surfaces: a state-of-the-art review. Comput Aided Des 42(7):641–654.  https://doi.org/10.1016/j.cad.2010.04.002 CrossRefGoogle Scholar
  7. 7.
    Zhu L, Li Z, Fang F, Huang S, Zhang X (2018) Review on fast tool servo machining of optical freeform surfaces. Int J Adv Manuf Technol 95(5):2071–2092.  https://doi.org/10.1007/s00170-017-1271-4 CrossRefGoogle Scholar
  8. 8.
    Thompson KP, Rolland JP (2012) Freeform optical surfaces: a revolution in imaging optical design. Opt Photonics News 23(6):30–35CrossRefGoogle Scholar
  9. 9.
    Savio E, De Chiffre L, Schmitt R (2007) Metrology of freeform shaped parts. CIRP Ann Manuf Technol 56(2):810–835CrossRefGoogle Scholar
  10. 10.
    Ohl Iv RG, Dow TA, Sohn A, Garrard K (2004) Highlights of the ASPE 2004 Winter Topical Meeting on Free-Form Optics: design, fabrication, metrology, assembly. In. pp 49-56Google Scholar
  11. 11.
    Wang X, Fu X, Li C, Kang M (2015) Tool path generation for slow tool servo turning of complex optical surfaces. Int J Adv Manuf Technol 79(1):437–448.  https://doi.org/10.1007/s00170-015-6846-3 CrossRefGoogle Scholar
  12. 12.
    Slavkovic NR, Milutinovic DS, Glavonjic MM (2014) A method for off-line compensation of cutting force-induced errors in robotic machining by tool path modification. Int J Adv Manuf Technol 70(9):2083–2096.  https://doi.org/10.1007/s00170-013-5421-z CrossRefGoogle Scholar
  13. 13.
    Liu X, Li Y, Xu X (2018) A region-based tool path generation approach for machining freeform surfaces by applying machining strip width tensor. Int J Adv Manuf Technol 98:3191–3204.  https://doi.org/10.1007/s00170-018-2427-6 CrossRefGoogle Scholar
  14. 14.
    Lazoglu I, Manav C, Murtezaoglu Y (2009) Tool path optimization for free form surface machining. CIRP Ann Manuf Technol 58(1):101–104CrossRefGoogle Scholar
  15. 15.
    Wolfs F, Fess E, DeFisher S, Torres J, Ross J (2015) Freeform grinding and polishing with PROSurf. Proc SPIE OptiFab G 96331Google Scholar
  16. 16.
    Murphy J (2015) Optics fabrication: changes, challenges and progress. Laurin Publ Co Inc Berkshire Common Po, PittsfielDGoogle Scholar
  17. 17.
    Su P, Oh CJ, Parks RE, Burge JH (2009) Swing arm optical CMM for aspherics. In: Optical manufacturing and testing VIII. International Society for Optics and Photonics, p 74260JGoogle Scholar
  18. 18.
    Jiang X, Scott P, Whitehouse D (2007) Freeform surface characterisation-a fresh strategy. CIRP Ann Manuf Technol 56(1):553–556CrossRefGoogle Scholar
  19. 19.
    Qiao J, Mulhollan Z (2016) Dorrer C Optical differentiation wavefront sensing for freeform optics metrology. In: Frontiers in optics. Optical Society of America, p FW5H. 5Google Scholar
  20. 20.
    Pant KK, Burada DR, Bichra M, Singh MP, Ghosh A, Khan GS, Sinzinger S, Shakher C (2015) Subaperture stitching for measurement of freeform wavefront. Appl Opt 54(34):10022–10028CrossRefGoogle Scholar
  21. 21.
    Khan G (2015) Non-null technique for measurement of freeform wavefront using stitching approach. In: Freeform optics. Optical Society of America, p FTh2B. 3Google Scholar
  22. 22.
    Khan G, Bichra M, Grewe A, Sabitov N, Mantel K, Harder I, Berger A, Lindlein N (2013) Sinzinger S Metrology of freeform optics using diffractive null elements in Shack-Hartmann sensors. In: 3rd EOS Conference on Manufacturing of Optical Components, pp 13–15Google Scholar
  23. 23.
    Burada DR, Pant KK, Mishra V, Bichra M, Khan GS, Sinzinger S, Shakher C (2017) Development of metrology for freeform optics in reflection mode. In: SPIE Optical Metrology. International Society for Optics and Photonics, p 103291K-103298Google Scholar
  24. 24.
    Burada DR, Pant KK, Bichra M, Khan GS, Sinzinger S, Shakher C (2017) Experimental investigations on characterization of freeform wavefront using Shack–Hartmann sensor. Opt Eng 56(8):084107.  https://doi.org/10.1117/1.OE.56.8.084107 CrossRefGoogle Scholar
  25. 25.
    Brunelle M, Yuan J, Medicus K, Nelson JD (2015) Importance of fiducials on freeform optics. In: SPIE Optifab. International Society for Optics and Photonics, pp 963318-963318-963318Google Scholar
  26. 26.
    Sohn A (2004) Fixturing and alignment of free-form optics for diamond turning. In: Proceedings of the American Society for Precision Engineering Winter Topical Meeting on Free-Form Optics: design, fabrication, metrology, assembly. CiteseerGoogle Scholar
  27. 27.
    Zhang X, Zeng Z, Liu X, Fang F (2015) Compensation strategy for machining optical freeform surfaces by the combined on- and off-machine measurement. Opt Express 23(19):24800–24810.  https://doi.org/10.1364/oe.23.024800 CrossRefGoogle Scholar
  28. 28.
    Chen S, Wu C, Xue S, Li Z (2018) Fast registration of 3D point clouds with offset surfaces in precision grinding of free-form surfaces. Int J Adv Manuf Technol 97(9):3595–3606.  https://doi.org/10.1007/s00170-018-2203-7 CrossRefGoogle Scholar
  29. 29.
    Chen C-C, Huang C-Y, Peng W-J, Cheng Y-C, Yu Z-R, Hsu W-Y (2013) Freeform surface machining error compensation method for ultra-precision slow tool servo diamond turning. Proc. SPIE, p 88380YGoogle Scholar
  30. 30.
    Ye H, Mingxu X, Xuezheng X, Zhaojun Y, Yinlong Z (2014) An accurate interpolator for FTS diamond turning of optical free-form surface. Int J Adv Manuf Technol 73(5):635–638.  https://doi.org/10.1007/s00170-014-5856-x CrossRefGoogle Scholar
  31. 31.
    Liu Q, Pan S, Yan H, Zhou X, Wang R (2016) In situ measurement and error compensation of optical freeform surfaces based on a two DOF fast tool servo. Int J Adv Manuf Technol 86(1-4):793–798CrossRefGoogle Scholar
  32. 32.
    Kim H-S, Lee K-I, Lee K-M, Bang Y-B (2009) Fabrication of free-form surfaces using a long-stroke fast tool servo and corrective figuring with on-machine measurement. Int J Mach Tools Manuf 49(12):991–997CrossRefGoogle Scholar
  33. 33.
    Zhu Z, To S (2015) Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics. Opt Express 23(16):20234–20248CrossRefGoogle Scholar
  34. 34.
    Mishra V, Pant K, Burada DR, Karar V, Khan G, Jha S (2017) Generation of freeform surface by using slow tool servo. In: Freeform Optics. Optical Society of America, p FTh3B. 2Google Scholar
  35. 35.
    Lindlein N, Simon F, Schwider J (1998) Simulation of micro-optical array systems with RAYTRACE. Opt Eng 37(6):1809–1817CrossRefGoogle Scholar
  36. 36.
    Mishra V, Khatri N, Nand K, Singh K, V Sarepaka R (2015) Experimental investigation on uncontrollable parameters for surface finish during diamond turning. Mater Manuf Process 30(2):232–240CrossRefGoogle Scholar
  37. 37.
    Mishra V, Khan GS, Chattopadhyay K, Nand K, Sarepaka RV (2014) Effects of tool overhang on selection of machining parameters and surface finish during diamond turning. Measurement 55:353–361CrossRefGoogle Scholar
  38. 38.
    Yu DP, Wong YS, Hong GS (2011) Optimal selection of machining parameters for fast tool servo diamond turning. Int J Adv Manuf Technol 57(1):85–99.  https://doi.org/10.1007/s00170-011-3280-z CrossRefGoogle Scholar
  39. 39.
    Chen C-C, Cheng Y-C, Hsu W-Y, Chou H-Y, Wang P-J, Tsai DP (2011) Slow tool servo diamond turning of optical freeform surface for astigmatic contact lens, vol 8126. SPIE Optical Engineering + Applications. SPIEGoogle Scholar

Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2019

Authors and Affiliations

  1. 1.CSIR-Central Scientific Instruments OrganizationChandigarhIndia
  2. 2.Indian Institute of Technology DelhiDelhiIndia

Personalised recommendations