Non-contact on-machine measurement using a chromatic confocal probe for an ultra-precision turning machine

On-machine measurement (OMM) involves the interruption of the machining process and the subsequent measurement of the workpiece without its removal from the machining tool. Chromatic confocal sensing is a well-known measurement technique that is able to evaluate the position of a point on an object surface along the optical axis of the system with high accuracy. The present study integrates a chromatic confocal measurement probe with an ultra-precision diamond turning machine to achieve the non-contact OMM of machined components. The procedure for establishing the position of the rotary axis of the spindle based on dual standard spheres is first described in detail, and the relevant OMM procedure for machined components of different surface topographies is explained. Then, a 50-μm quartz step height standard is employed to investigate the linear measurement accuracy of the chromatic confocal probe. Finally, the measurement accuracy of the proposed OMM method is compared experimentally with that of the stylus method. The results show that the estimated form error value of the OMM method agrees well with the value obtained by the stylus method. The proposed OMM method feasibly achieves non-contact OMM with a nanometer-level accuracy for an ultra-precision turning machine and is capable of reconstructing the 3D surface topography of flat, spherical, and aspheric surfaces. After integrating the OMM method, the ultra-precision turning machine can realize the function of processing-measurement integration.

[1]  M. Shiraishi,et al.  Scope of in-process measurement, monitoring and control techniques in machining processes—Part 2: In-process techniques for workpieces , 1988 .

[2]  Kuang-Chao Fan,et al.  In-process dimensional control of the workpiece during turning , 1991 .

[3]  M. Burdekin,et al.  In-process dimensional measurement and control of workpiece accuracy , 1997 .

[4]  Masatake Shiraishi,et al.  In-Process Measurement of Dimensional Error for Stepped Workpiece Profile , 1998 .

[5]  Zhan-Qiang Liu,et al.  Repetitive Measurement and Compensation to Improve Workpiece Machining Accuracy , 1999 .

[6]  Takanori Yazawa,et al.  Radial shearing interferometer for in-process measurement of diamond turning , 2000 .

[7]  Takamasa Suzuki,et al.  Measurement of cylinder diameter by using sinusoidally vibrating sinusoidal gratings , 2001, Optical Engineering for Sensing and Nanotechnology.

[8]  C. Z. Li,et al.  The Measurement and Control of Diameter in Large-Scale Part Processing , 2002 .

[9]  Richard Tomlinson,et al.  Synthetic aperture interferometry: in-process measurement of aspheric optics. , 2003, Applied optics.

[10]  Samir Mekid,et al.  In-process dimensional inspection sensors , 2005 .

[11]  Tae Jo Ko,et al.  On-machine measurement using a noncontact sensor based on a CAD model , 2007 .

[12]  X. Su,et al.  3D shape measurement of the aspheric mirror by advanced phase measuring deflectometry. , 2008, Optics express.

[13]  Mahmudur Rahman,et al.  Development of an on-machine profile measurement system in ELID grinding for machining aspheric surface with software compensation , 2008 .

[14]  Young-bong Bang,et al.  Fabrication of free-form surfaces using a long-stroke fast tool servo and corrective figuring with on-machine measurement , 2009 .

[15]  Shaohui Yin,et al.  Profile error compensation in ultra-precision grinding of aspheric surfaces with on-machine measurement , 2010 .

[16]  Yongsheng Gao,et al.  An in-process form error measurement system for precision machining , 2010 .

[17]  Yinbiao Guo,et al.  A Machining Error Compensation Method Using on-Machine Profile Measurement in 3-Axis Aspheric Grinding , 2010 .

[18]  D. Luo,et al.  Fiber-based chromatic confocal microscope with Gaussian fitting method , 2012 .

[19]  Christophe Tournier,et al.  In situ non-contact measurements of surface roughness , 2012 .

[20]  Zhu Yongjian,et al.  Discussions on on-machine measurement of aspheric lens-mold surface , 2013 .

[21]  S. Bettoni,et al.  Chromatic confocal setup for displacement measurement using a supercontinuum light source , 2013 .

[22]  Tao Sun,et al.  Study on the auto-leveling adjustment vibration isolation system for the ultra-precision machine tool , 2014, Other Conferences.

[23]  G. L. Samuel,et al.  Evaluation of Surface Profile Parameters of a Machined Surface Using Confocal Displacement Sensor , 2014 .

[24]  H. Nouira,et al.  Characterization of the main error sources of chromatic confocal probes for dimensional measurement , 2014 .

[25]  Zhenyuan Jia,et al.  Integration strategy of on-machine measurement (OMM) and numerical control (NC) machining for the large thin-walled parts with surface correlative constraint , 2015 .

[26]  Nuodi Huang,et al.  Identification of geometric errors of rotary axes on 5-axis machine tools by on-machine measurement , 2016 .