Automatic selection of image features for visual servoing of a robot manipulator

The authors investigate the selection of image features to be used to control visually the position and orientation (pose) of the end-effector of an eye-in-hand robot relative to a workpiece. A resolved-motion-rate control scheme is used to update the robot´s pose on the basis of the position of three features in the camera´s image. The selection of these three features depends on the condition and sensitivity of the differential relationship between the image features and the control parameters. Both computer simulations and laboratory experiments on a PUMA robot arm were conducted to verify the performance of the feature selection criteria. Experimentally, the PUMA robot arm, with a CCD (charged-coupled device) camera mounted on its end effector, was able to track a randomly moving carburetor gasket with a visual feedback cycle time of 70 ms