Phase-based Multi-DOF Precision Position Measurement and Applications

Date: 2023/02/20 - 2023/02/20

Dissertation Title: Phase-based Multi-DOF Precision Position Measurement and Applications

Speaker: Qinrui Cheng, Ph.D. candidate at UM-SJTU Joint Institute

Time: 8:00 p.m., Februray 20th, 2023 ( Beijing Time)

Location: Room 414A, Longbin Building


Precision positioning is fundamental and critical in many fields of advanced industry and manufacturing, such as semiconductor production, machine tools control, and robot manipulation. Position measurement systems are demanded towards multi-degree-of-freedom (multi-DOF) measurement simultaneously with high resolution and large range. This dissertation presents a monocular vision method for high-precision 3-DOF and 6-DOF position measurement and extended applications on motion stage calibration and camera calibration. A simple system configuration with one industrial camera and a 2D encoded periodic pattern is employed. The phase estimation method is applied for high-accuracy and robust keypoint localization within one period of pattern. The findings from this dissertation have significant improvement and guidance upon phase-based position measurement and application design of the vision systems.


Qinrui Cheng received the B.S. and M.S. degrees in instrument science and technology from Tianjin University in 2016 and 2019, respectively. She is currently a Ph.D. candidate at the UM-SJTU Joint Institute, supervised by Prof. Peisen Huang. Her current research interests include precision measurement, computer vision, optical metrology, and image processing.