title: Robust contact detection in micromanipulation using computer vision microscopy.
abstract: This paper presents a computer vision algorithm for visually detecting the contact between an end-effector and a target surface under an optical microscope. Without using additional sensors (e.g., proximity or force/touch sensors), this algorithm provides robustness and a sub-micrometer detection resolution. Fundamentally, after the establishment of a contact in the world frame, further vertical motion induces horizontal motion in the image plane. An analysis is presented to elaborate this fundamental mechanism. Experimental results demonstrate that this computer-vision-based method is capable of achieving contact detection between a micropipette and a glass slide surface with a resolution of 0.2 microm. Furthermore, 1300 experimental trials reveal that the presented algorithm is robust to variations in illumination intensity, microscopy magnification, and microrobot motion speed.
authors.affiliation: Advanced Micro & Nanosystems Laboratory, University of Toronto, Ontario, Canada.
authors.forename: W H
authors.initials: WH
authors.lastname: Wang
authors.forename: X Y
authors.initials: XY
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008846:Micromanipulation / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012371:Robotics / Q000379:methods*; D012680:Sensitivity and Specificity; D013499:Surface Properties