Prof. Benny C. F. Cheung, Hong Kong Polytechnic University, China

Title

Ultra-precision Diamond-machined Polar Microstructure for Computer Vision-based Precision Positioning and Nanoscale Measurement

Abstract

In this presentation, a computer vision-based precision positioning method is presented which is developed based on a purposely designed polar microstructured surface and template matching based computer vision technology. The surface features of the polar micro-structured surface are composed of concentric circles and straight lines equal spaced which is fabricated by a process chain of ultra-precision machining technology combining single point diamond turning (SPDT) and single point diamond grooving (SPDG). The polar microstructure surface attempts to provide the surface features for the construction of unique pixel intensity distribution which serve as a global map for the subsequent matching measurement. For computer vision, it makes use of the template-matching and sub-pixel interpolation method as the basic working principle to match the position on the polar microstructure surface.  The template matching algorithm is used for image processing and determine the absolute position of the selected image in the global map, the sub-pixel interpolation is used to improve the pixel resolution to nanometric level. A series of experiments have been conducted to evaluate the accuracy of positioning measurement. The experimental results show that the proposed method is feasible to achieve nanometric level of uncertainty. The proposed computer vision-based precision positioning method has great potential to be applied in workpiece positioning, nanoscale measurement, and measurement of accuracy and repeatability of positioning of the machine tool in the future.

Biography

Prof. Benny C.F. Cheung is a Professor and the Head of the State Key Laboratory of Ultra-precision Machining Technology at the Department of Industrial and Systems Engineering (ISE) of The Hong Kong Polytechnic University. His research interests in precision engineering include ultra-precision machining, precision metrology, advanced optics manufacturing, etc. Up to present, he has authored and co-authored two Research Monographs, three Edited Books, five Book Chapters and more than 250 refereed journal papers including more than 160 Science Citation Indexed (SCI)/Social Science Citation Indexed (SSCI) refereed journal papers. 

Currently, he holds various honorary positions in other universities and professional bodies including Board Membership of the Asian Society for Precision Engineering and Nanotechnology (ASPEN), etc. He was offered the Senior Research Fellowship at Durham University under the Durham International Fellowships for Research and Enterprise in 2017. Prof. Cheung has received many research prizes and awards such as the 2008 ASAIHL-Scopus Young Scientist Awards–First Runner Up Prize in the category of “Engineering and Technology”, Joseph Whitworth Prize 2010 by the Manufacturing Industrial Division of The Institution of Mechanical Engineers (IMechE), UK in 2011,Winner of the IET Innovation Award–Manufacturing Technology, The Institution of Engineering and Technology (IET), UK (2017), etc.