Patent ID: 6603870
Filing Date: 2003-08-05
Classification: G06K,G06T

Abstract:
A method for visual servoing of a linear apparatus for aiming at a fixed target, said linear apparatus being rotatable in a defined plane about a fixed point, and wherein said linear apparatus and target are viewed by an imaging process in a two-dimensional (2D) image plane, said method comprising the steps of:beginning at an arbitrary first line direction in space of said linear apparatus, detecting and storing an image of said first line direction in said 2D image plane; detecting and storing an image of said fixed target in said 2D image plane; rotating said linear apparatus through a first angle in said defined plane about said fixed point to a second line direction; detecting and storing an image of said second line direction in said 2D image plane; rotating said linear apparatus through a second angle in said defined plane about said fixed point to a third line direction; detecting and storing an image of said third line direction in said 2D image plane; determining and storing the point of intersection in said 2D image plane of said images of said first, second, and third line directions; storing an image of a virtual straight line in said 2D image plane passing through said image of said fixed target in said 2D image plane and said point of intersection, said image of a virtual straight line being associated with a corresponding virtual line passing through said fixed point and said target; determining the cross-ratio of said 2D images of said first, second, third, and virtual line directions; calculating from said cross-ratio an aiming angle between said third and said virtual line directions in 3D space; and aligning said linear apparatus along said virtual line in accordance with said aiming angle so as to visually aim at said target.