A Simple but Useful Approach to Monocular Eye-in-Hand Robotic Orientation Calibration

In this paper we present a way to automatically recover camera orientation in an eye-in-hand system. The algorithm is completely automated performing a sequence of rotations and translations iteratively until the camera frame has been successfully aligned with the manipulators world frame. The system we have developed has been fully implemented and tested on a Staubli RX60 robotic arm using an off-the-shelf Logitech USB camera. The algorithms were developed in both the Java and V+ programming languages, which for our purposes needed to communicate together. In our tests we use vision algorithms to snap a series of pictures of a black blob on a white background, working to center the object. Data from these algorithms are processed using manipulator algorithms developed in V+. These data indicate what movements should be made by the end effector. These movements are made incrementally until the camera and the Robots world frame are aligned. In our experimental results the algorithms successfully converged for each test and the unknown angles were successfully recovered. Our experiments and results in this paper present a novel way to recover camera orientation during recalibration. The system presented in the following sections can provide an efficient way to automatically allow a manipulator to maintain precision throughout operation.