A hybrid neural control scheme for visual-motor coordination

Visual-motor coordination, also referred to as hand-eye coordination, in the context of robotics is the process of using visual information to control a robot manipulator to reach a target point in its workspace. The task requires learning the mapping that exists between camera output and desired end effector location. Biological organisms have demonstrated their superior adaptive capabilities in motion control over present-day robotic systems. Inspired by this fact, various neural network models based on biological systems have been developed for robot control tasks. The drawback of many neural schemes to tackle visual-motor control problems is that of a long training period. We suggest an approach using Kohonen's self-organizing scheme to learn this hand-eye coordination problem in reduced time with high accuracy. Our approach has also been compared with a conventional calibration-based algorithm. These schemes have been implemented in real time on a CRS PLUS robot arm. Experimental results show that the proposed neural scheme is on an average 10 times faster in training compared to similar neural approaches existing in the literature. This speed is also comparable to the conventional algorithm and is more accurate.