Teleoperating Robots in Multiuser Virtual Environments Moisés Alencastre-Miranda, Lourdes Muñoz-Gómez, Isaac Rudomín Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Estado de México. Carretera Lago de Guadalupe Km 3.5, Atizapán de Zaragoza, Estado de México, C.P. 52926, México. {00471699, 00709911}@academ01.cem.itesm.mx, rudomin@itesm.mx Abstract In the last few years, robot teleoperation systems have been improved with the advances in computer networks, virtual reality and graphical user interfaces. However, teleoperation applications for multiple and different robots in networked virtual environments are not available for all kind of users. This paper presents a collaborative multiuser system for multiple simultaneous robot teleoperation. We describes the object oriented distributed architecture used and the system modules developed. The system implementation shows a visual simulation based on a networked virtual environment. The system allows different kinds of manipulators and mobile robots, either virtual or real. The feasibility of the system has been successfully demonstrated with some experiments. 1. Introduction Teleoperation allows an operator in a specific place to execute a task on another place, possibly separated by large distances [1]. Teleoperation systems have four main components: 1. The master device, which is an input interface that the operator uses to control the system. 2. The slave device, which is an output device that executes actions requested by the operator in a remote place. 3. The physical communication scheme between the two places. 4. The remote visual monitoring of the tasks performed by the slave device, also called telemonitoring. A Virtual Environment (VE), is the representation of the computational geometric modeling of a real environment in a 3D visual simulation created with computer graphics techniques [2]. Networked virtual environments (net-VEs) allow multiple users in different geographical locations to interact in a common virtual environment [3]. These systems allow collaboration between different groups of users over a network to perform a common task. Net-VEs are mainly used for military and industrial equipment training, engineering and multiuser games. In [4], Singhal and Zyda identify a net-VE by the following features: 1. A shared sense of space. All participants have the feeling of being located in the same place. The shared space must have the same visual features for all participants. 2. A shared sense of presence. Each participant can be identified by using a graphical representation in the virtual environment. This representation can be human or not. 3. A shared sense of time. Participants must see other participant behaviors in the moment in which these behaviors are taking place. 4. A communication mechanism. There must exist communication between participants using voice or text. 5. A sharing mechanism. The importance of a net-VE lies in the ability of the users to interact with other participants in the virtual environment. Therefore, in the last years, advances in graphical user interfaces (GUIs), robotics, computer networks and VEs allow the teleoperation system components to evolve into “robot teleoperation systems”: • Master devices have changed from mechanical or electrical manipulator devices to input devices (like joysticks and wheels) and GUIs. • Slave devices were mechanical or electrical manipulators, but now they can be either a manipulator or a mobile robot (virtual or real). A virtual robot is the 3D visual simulation of a real robot in a VE. • Currently, the physical communication scheme is based on computer networks (wireless networks could be used). • Monitoring in teleoperation systems was initially implemented using closed circuit TV and has evolved to use video cameras, transmitting images or compressed video through the net.