Hand/eye calibration of a robot arm with a 3D visual sensor

Hand/eye calibration is useful in many industrial applications, for instance, grasping objects or reconstructing 3D scenes. The calibration of robot systems with a visual sensor is essentially the calibration of a robot, a sensor, and hand-to-eye relation. This paper describes a new technique for computing 3D position and orientation of a 3D visual sensor system relative to the end effector of a robot manipulator in an eye-on-hand robot configuration. When the position of feature points on a calibration target in sensor coordinates viewed at each robot movement, and the position of these points in world coordinates and the relative robot movement between two robot motions are known, a homogeneous equation of the form AX = XB can be derived. To obtain the unique solution of X, it is necessary to make two relative robot arm movements and to form a system of two equations of the form: A₁X = XB₁and A₂X = XB₂. In this paper, a closed-form solution of this calibration system is derived, and the constraints for existence of a unique solution are described in detail. Test results obtained through a series of simulation show that this technique is a simple, efficient, and accurate method for hand/eye calibration.