Image-based calibration for micro manipulators

Calibration is indispensable for automatic micromanipulation. In this paper, using the height difference between different focus planes detected from the microscope and the coordinates of the probe measured from encoders, systematic method to calibrate the relative orientation between the probe and the microscope is developed. By analyzing and overlapping the images under different focus planes, the tip position and tool orientation are also derived. Using the Least Square Error (LSE) method to process the data measured, the influence of various positioning errors can be reduced. Experiments are performed to calibrate a micromanipulation system using the proposed methods. The calibration results are validated by cross verification through further experiments.