Abstract: When manipulator grasps intelligently the workpiece, the acquisition of grasping position
about workpiece is the key of accurate assembly based on machine vision. For the grabbing link on
assembly of packing tubular workpiece in the more complex environment as the object of study, a
reasonable machine vision system is established, and the method combined with Gaussian fitting and
Hough transform is proposed by using the feature of the forward lighting system reflecting straight light
on the surface of workpiece. Firstly, Gaussian fitting method is used to extract the center coordinates of
each light stripe in normal direction, then the coordinates of point set is fitted by using Hough transform,
finally the workpiece grasping position is calculated according to the obtained each light center line. The
experimental results show that this method not only can achieve the fitting of multiple light line, and can
suppress interference and noise commendably, and effectively realize the intelligent acquisition of
grasping position of packing workpiece.

Key words: machine vision, Gaussian fitting, Hough transform, the centerline of light stripe, the
grasping position