Robust contact detection in micromanipulation using computer vision microscopy.
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.
Wang
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Advanced Micro & Nanosystems Laboratory, University of Toronto, Ontario, Canada.
Liu
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Sun
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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