<title>Virtual reality: an intuitive approach to robotics</title>

Abstract

Tasks definition for manipulators or robotic systems (conventional or mobile) usually lack on performance and are sometimes impossible to design. The `On-line' programming methods are often time expensive or risky for the human operator or the robot itself. On the other hand, `Off-line' techniques are tedious and complex. In a virtual reality robotics environment (VRRE), users are not asked to write down complicated functions to specify robotic tasks. However a VRRE is only effective if all the environment changes and object movements are fed-back to the virtual manipulating system. Thus some kind of visual or multi-sensor feedback is needed. This paper describes a semi autonomous robot system composed of an industrial 5-axis robot and its virtual equivalent. The user is immersed in a 3-D space built out of the robot's environment models. He directly interacts with the virtual `components' in an intuitive way creating trajectories, tasks, and dynamically optimizing them. A vision system is used to recognize the position and orientation of the objects in the real robot workspace, and updates the VRRE through a bi-directional communication link. Once the tasks have been optimized on the VRRE, they are sent to the real robot and a semi autonomous process ensures their correct execution thanks to a camera directly mounted on the robot's end effector. Therefore, errors and drifts due to transmission delays can be locally processed and successfully avoided. The system can execute the tasks autonomously, independently of small environmental changes due to transmission delays. If the environmental changes are too important the robot stops re-actualizes the VRRE with the new environmental configuration and waits for task redesign.