In order to have an operative system with multiple robots each one with its own configuration, it is important to establish cooperative mechanisms that allow the robots with less sensory power to get helped from the robots with more sensory power. In this context, it is important that the cooperation is done in a way that allows each robot to take advantage of the particular resources of the other robots in the system. This paper presents an application where a group of robots must cooperate in order to safely navigate through an unknown environment. In this application, only one robot has a camera mounted on it and none of the other robots have any type of sensor. The robot with the camera calculates the optical flow values from the images that it gets from the camera, and from these values calculates the ldquotime to contactrdquo values that determine the time that the robot has before colliding with an obstacle in front of it. This information is shared among the team so that any robot can navigate without colliding with the obstacles.

We present an agent-based framework for the development of distributed applications for a team of heterogenous mobile robots. The main goal is to ease the development of cooperative tasks among teams of robots. The proposed architecture must have not only the capacity to allow the team of robots to accomplish such tasks, but also it must have tools and features that allow programmers to develop complex applications in a reasonable time. Agent-based development platforms are used for this purpose, integrating the necessary capabilities for developing distributed applications, and managing the communications among all the components. To demonstrate the advantages of the proposed framework, two real applications, remote vision and robot following, are presented. Both of them consist of a set of agents, and run actually in real robot systems, demonstrating that distributed systems do not add significant overhead to real-time tasks.

The design of online robots is a difficult task that must take into account multiple aspects like for example: (1) the system architecture, (2) the user interface, (3) communications, (4) time delay, (5) limited bandwidth, etc. Besides this, taking into account that the Web permits multiple people to easily access a single system, methods for managing the control of a unique robot must be designed (e.g. off-line virtual interfaces, connecting several robots to the system, etc.). In this paper we present the system architecture that have been used in our laboratory to let users program remotely two educational and two industrial robots through the same Web based system. Experimental results show different alternatives to organize the architecture and focus on the system performance aspects.

In this paper, we present the system architecture that has been used in order to implement a whole Internet-based tele-laboratory, which allows researchers and students to program remotely an online robot. In fact, the challenge has been demonstrating that remote programming combined with an advanced multimedia user interface for remote control is very convenient, flexible and profitable for the design of the tele-laboratory. In fact, the contribution consist of designing a system architecture that permits to any external program (i.e. remote experiment, speech recognition module, etc.) to have access to almost every feature of the already existing "UJI online robot" (i.e. cameras, object recognition, robot control, etc.) [R. Martin, et al., May 2002].

In the last years, there is a greater interest in systems of multiple autonomous robots for the accomplishment of cooperative tasks. This fact has motivated the implementation of a distributed architecture for a team of heterogeneous mobile robots. Such architecture must have the capacity to allow to the team of robots the accomplishment of cooperative tasks; the proposed solution consist of a multiagent system for the implementation of this distributed architecture. Also, two practical applications of cooperative tasks with the created architecture are sketched: cooperative navigation and localization and cooperative visual servoing.