| Volume 26 Issue 8 - Publication Date: 1 August 2007 |
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| Contact Detection in Microrobotic Manipulation |
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| W. H. Wang, X. Y. Liu, and Y. Sun Advanced Micro and Nanosystems Laboratory, University of Toronto,Canada |
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| This paper presents a computer vision-based method for visually detecting
the contact between an end-effector and a target surface under
an optical microscope during microrobotic manipulation.Without
using proximity or force/touch sensors, this method provides a submicrometer
detection accuracy and possesses robustness. Fundamentally,
after the establishment of contact in the world frame, further
vertical motion of the end-effector (flexible or stiff) induces horizontal
motion in the image plane. Contact between a micropipette tip and
a glass slide in the scenario of microrobotic cell manipulation is used
as an example to elaborate on the detection method. Experimental results
demonstrate that the computer vision-based method is capable
of achieving contact detection between the micropipette and the glass
slide surface with an accuracy of 0.2 m. Furthermore, 1000 experimental
trials reveal that the presented method is robust to variations
in illumination intensity, microscopy magnification, and microrobot
motion speed. |
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| Multimedia Key |
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Extension |
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Description |
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Example
1: After the establishment of contact in the world frame, further vertical motion of the end-effector induces
horizontal motion in the image plane. Detection of the contact between the end-effector and target
surface is equivalent to locating the global minimum of x coordinates of the end-effector in the image
plane with either a pixel resolution or sub-pixel resolution method. (3.5 MB) mpgi |
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