Self-Calibration Vision Method and System for Automatically Moving CMM Stylus Into Micro Holes

The components with micro deep holes have massive presence in different major equipment or systems. Coordinate measuring machine (CMM) remains the main equipment to measure these components because non-contact methods cannot be applied to micro deep holes. However, moving probe tips into micro holes accurately is extremely difficult for CMM through existing methods. Therefore, this study puts forward a self-calibration and high-precision vision method and system. The algorithm for automatic determination of the probe tip movement scheme is proposed, several suitable image processing methods are selected, and the vision system is designed and tested on CMM. Experimental results show that a probe tip with a diameter of
$60 \boldsymbol {\mu }\text{m}$
can be moved into micro holes below
$100 \boldsymbol {\mu }\text{m}$
with a success rate of 100%. This method and system can be used to provide an effective means for highly precise and fast measurement of micro holes.