Machine-vision-guided rotation axis alignment for an optomechanical derotator

An image derotator is a device that can compensate the image blur caused by the rotation of an object. However, a key problem when using a derotator is to ensure the coincident alignment between the rotation axes of the derotator and measured object. An approach of machine-vision-guided rotation axis alignment is proposed in this paper. Circular markers and a laser dot are deployed to indicate the rotation axes of the derotator and object, respectively. A binocular stereo sensor is established to estimate the poses of both axes. With the misalignment information between the two axes updated in real-time, axis alignment can be achieved through manual adjustment. The validity and precision of the proposed approach are demonstrated through experiments.