Sara Fleury

Multi-robot cooperation in the MARTHA project

The MARTHA project objectives are the control and the management of a fleet of autonomous mobile robots for transshipment tasks in harbors, airports and marshalling yards. One of the most challenging and key problems of the MARTHA project is multi-robot cooperation. A general concept for the control of a large fleet of autonomous mobile robots has been developed, implemented and validated in the framework of the MARTHA project. This is the first study in the autonomous mobile robot field to add multi-robot cooperation capabilities to such a large fleet of robots.

G/sup en/oM: a tool for the specification and the implementation of operating modules in a distributed robot architecture

This paper presents a general methodology for the specification and the integration of functional modules in a distributed reactive robot architecture. The approach is based on a hybrid architecture basically composed of two levels: a lower distributed functional level controlled by a centralized decisional level. Due to this methodology, synchronous or asynchronous operating capabilities (servo-control, data processing, event monitoring) can be easily added to the functional level. They are encapsulated into modules, built according to a generic model, that are seen by the decisional level as homogeneous, programmable, reactive and robust communicant services. Each module is simply described with a specific language and is automatically produced by a generator of modules (G/sup en/oM) according to the generic model. G/sup en/oM also produces an interactive test program and interface libraries to control the module and to read the resulting data, which allow one to directly integrate the module into the architecture.

Design of a modular architecture for autonomous robot

This paper proposes a formalism for the description and automated implementation of the functional modules of an autonomous mobile robot in the framework of multi-layered control architectures. The formalization of the description of a module, including its behavior and its interfaces with other modules makes the implementation easier by providing higher level tools and automatic consistence checking tools in the module compiler. The execution control level can take advantage of the formal description of the activity tree of the modules to manage the resources more efficiently. A global task of the robot is achieved by the control system by connecting the modules into a dynamic activity tree. Finally the authors present a modules compiler that uses the formal module description and user supplied functions to produce the modules in an automated way.<<ETX>>

Autonomous Rover Navigation on Unknown Terrains Functions and Integration

Autonomous long range navigation in partially known planetary-like terrain is an open challenge for robotics. Navigating several hundreds of meters without any human intervention requires the robot to be able to build various representations of its environment, to plan and execute trajectories according to the kind of terrain traversed, to localize itself as it moves, and to schedule, start, control and interrupt these various activities. In this paper, we briefly describe some functionalities that are currently running on board the Marsokhod model robot Lama at LAAS/CNRS. We then focus on the necessity to integrate various instances of the perception and decision functionalities, and on the difficulties raised by this integration.

Autonomous navigation in outdoor environment: adaptive approach and experiment

This paper presents the approach, algorithms and processes we developed to perform cross-country autonomous navigation. After a presentation of the teleprogramming context, we introduce an adaptive navigation approach, well suited for the characteristics of complex natural environments. The main perception, motion planning and decisional processes required by the robot during navigation are briefly presented. An on board control architecture that manages all these processes is then described, and first results of an experiment currently developed at LAAS are discussed.<<ETX>>

Rackham: An Interactive Robot-Guide

Rackham is an interactive robot-guide that has been used in several places and exhibitions. This paper presents its design and reports on results that have been obtained after its deployment in a permanent exhibition. The project is conducted so as to incrementally enhance the robot functional and decisional capabilities based on the observation of the interaction between the public and the robot. Besides robustness and efficiency in the robot navigation abilities in a dynamic environment, our focus was to develop and test a methodology to integrate human-robot interaction abilities in a systematic way. We first present the robot and some of its key design issues. Then, we discuss a number of lessons that we have drawn from its use in interaction with the public and how that will serve to refine our design choices and to enhance robot efficiency and acceptability

A specification of generic robotics software components: future evolutions of G/sup en//sub o/M in the Orocos context

Robotics systems and software are becoming more and more complex: the need of standard specifications is certainly a key issue in the near future. There is a need to define, from the software point of view, a generic robot. The Orocos project was started to address this problem. It aims at developing a set of robotics software in particular domains and, as a first step, will define a software framework to do that. This paper presents the future evolutions of G/sup en/oM (component generator) which we propose as a programming framework in the context of the project. G/sup en/oM proposes the definition of generic components that are used to implement robotics functionalities (vision, control, motion planning, ...), and the paper presents the definition of those components. They have been designed so that they can be connected together and externally controlled to form a modular functional layer on robots. We have defined three main entities of which components are made: a set of algorithms, an execution engine, and a communication library. The paper explains their role and presents a formal description language that let us achieves a real decoupling between code of the components (the algorithms) and the execution engine.

Ten autonomous mobile robots (and even more) in a route network like environment

This paper presents an implemented system which allows one to run a fleet of autonomous mobile robots in a route network with a very limited centralized activity. The robots are provided with all the necessary ingredients for planning and executing navigation missions in a multi-robot context. Multi-robot cooperation is based on a generic paradigm called plan-merging paradigm, where robots incrementally merge their plans into a set of already coordinated plans. The robot architecture is derived from the generic architecture developed at LAAS. A 3D graphic environment system allows one to display a complete system composed of a dozen (or more) robots, each running on an independent workstation. An example is presented together with numerical results on the system behavior.

Autonomous Navigation in Natural Environments

This paper presents the approach, algorithms and processes we developed to perform autonomous navigation in a natural environment. After a description of the global approach, we discuss the characteristics of natural environment representations. Then the perception functions for terrain mapping and robot localization, as well as motion planning are described. Navigation strategies for selecting perception tasks and subgoals for motion planning are proposed. The current state of integration in the experimental test bed EDEN is finally presented. Results from this experiment illustrate the approach troughout the paper.

A General Framework For Multi-Robot Cooperation and Its Implementation on a Set of Three Hilare Robots

We present a general concept for the control of a large fleet of autonomous mobile robots which has been developed, implemented and validated through various experiments.