An autonomous robot offers a challenging and ideal field for the study of intelligent architectures. Autonomy within a rational be havior could be evaluated by the robot's effectiveness and robust ness in carrying out tasks in different and ill-known environments. It raises major requirements on the control architecture. Further more, a robot as a programmable machine brings up other archi tectural needs, such as the ease and quality of its specification and programming. This article describes an integrated architecture that allows a mobile robot to plan its tasks—taking into account temporal and domain constraints, to perform corresponding actions and to con trol their execution in real-time—while being reactive to possible events. The general architecture is composed of three levels: a de cision level, an execution level, and a functional level. The latter is composed of modules that embed the functions achieving sensor- data processing and effector control. The decision level is goal and event driven, and it may have several layers, according to the application; their basic structure is a planner/supervisor pair that enables the architecture to integrate deliberation and reaction. The proposed architecture relies naturally on several representa tions, programming paradigms, and processing approaches, which meet the precise requirements that are specified for each level. The authors have developed proper tools to meet these specifications and implement each level of the architecture: a temporal planner, IxTeT; a procedural system for task refinement and supervision, PRS; Kheops for the reactive control of the functional level, and GenoM for the specification and integration of modules at that level Validation of the temporal and logical properties of the reactive parts of the system, through these tools, are presented. Instances of the proposed architecture have been integrated into several indoor and outdoor robots. Examples from real-world ex perimentations are provided and analyzed.

International audienceAutonomous robots facing a diversity of open environments and performing a variety of tasks and interactions need explicit deliberation in order to fulfill their missions. Deliberation is meant to endow a robotic system with extended, more adaptable and robust functionalities, as well as reduce its deployment cost. The ambition of this survey is to present a global overview of deliberation functions in robotics and to discuss the state of the art in this area. The following five deliberation functions are identified and analyzed: planning, acting, monitoring, observing, and learning. The paper introduces a global perspective on these deliberation functions and discusses their main characteristics, design choices and constraints. The reviewed contributions are discussed with respect to this perspective. The survey focuses as much as possible on papers with a clear robotics content and with a concern on integrating several deliberation functions

In the immediate future, metrics related to safety and dependability have to be found in order to successfully introduce robots in everyday environments. The crucial issues needed to tackle the problem of a safe and dependable physical human-robot interaction (pHRI) were addressed in the EURON Perspective Research Project PHRIDOM (Physical Human-Robot Interaction in Anthropic Domains), aimed at charting the new "territory" of pHRI. While there are certainly also "cognitive" issues involved, due to the human perception of the robot (and vice versa), and other objective metrics related to fault detection and isolation, the discussion in this paper will focus on the peculiar aspects of "physical" interaction with robots. In particular, safety and dependability will be the underlying evaluation criteria for mechanical design, actuation, and control architectures. Mechanical and control issues will be discussed with emphasis on techniques that provide safety in an intrinsic way or by means of control components. Attention will be devoted to dependability, mainly related to sensors, control architectures, and fault handling and tolerance. After PHRIDOM, a novel research project has been launched under the Information Society Technologies Sixth Framework Programme of the European Commission. This "Specific Targeted Research or Innovation" project is dedicated to "Physical Human-Robot Interaction: depENDability and Safety" (PHRIENDS). PHRIENDS is about developing key components of the next generation of robots, including industrial robots and assist devices, designed to share the environment and to physically interact with people. The philosophy of the project proposes an integrated approach to the co-design of robots for safe physical interaction with humans, which revolutionizes the classical approach for designing industrial robots - rigid design for accuracy, active control for safety - by creating a new paradigm: design robots that are intrinsically safe, and control them to deliver performance. This paper presents the state of the art in the field as surveyed by the PHRIDOM project, as well as it enlightens a number of challenges that will be undertaken within the PHRIENDS project

The development of systems capable of handling and diagnosing malfunctions in real time has long been of considerable practical importance. This paper describes the architecture of such a system, called the Procedural Reasoning System (PRS). PRS is based on the notion of a rational agent that can reason and plan under possibly stringent constraints on both time and information. This approach p r o vides the system with the ability to reason in complex ways about dynamic processes, while still maintaining the reactivity required to ensure appropriate responsiveness and control. By considering two large-scale applications in aerospace and telecommunications, it is shown how PRS meets many of the critical requirements for real-time malfunction-handling and diagnostic systems. Finally, PRS is compared with a number of other real-time reasoning and knowledge-based architectures that have been used in similar applications.

The Martha 1 project objectives are the control and the management of a eet of autonomous mobile robots for transshipment tasks in harbours, airports and marshaling yards. Our presentation focuses on one of the most challenging and key problems of the Martha project: the multi robot cooperation. Indeed, high level missions are produced by a Central Station and sent to robots. It is then up to the robots to re ne their missions, to plan their actions and trajectories in the environment and to coordinate these actions and trajectories with the other robots. In particular, these coordinations occur in crossings, in lanes when unexpected obstacles require the robot to move in the opposite lane, and in open areas where robots need to synchronise their trajectories.We present a general concept for the control of a large eet of autonomous mobile robots which has been developed, implemented and validated in the framework of Martha.Numerous researches have been conducted in the autonomous mobile robot eld, nevertheless, the Martha project is the rst one to add the multi robot cooperation capabilities to such a large eet of robots.The Martha robots demonstrate advanced autonomous features including non-holonomic motion planning, environment modelling, sensor-based obstacle avoidance, and decentralised cooperation schemes at mission and trajectory levels.

In this paper, we discuss Procedural Reasoning System (PRS) as a high level Control and Supervision language adapted to autonomous robots to represent and execute procedures, scripts and plans in dynamic environments. We discuss the main reasons why PRS is well suited for this type of application: (1) The semantics of its plan (procedure) representation, which is important for plan execution and goal re nement (2) Its ability to construct and act on partial (rather than complete) plans (3) Its ability to pursue goal-directed tasks while at the same time being responsive to changing patterns of events in bounded time (4) Its facilities for managing multiple tasks in real-time (5) Its default mechanisms for handling stringent real-time demands of its environment and (6) Its meta-level (or re ective) reasoning capabilities. C-PRS 1 has been used to implement an embedded c ontrol and supervision system for autonomous mobile robots in two di erent experimentations that we brie y present (Eden and Martha). We conclude with some suggestions to further develop C-PRS and with a short review of related work.

The topic of reusable software in robotics is now largely addressed. Components based architectures, where components are independent units that can be reused accross applications, have become more popular. As a consequence, a long list of middlewares and integration tools is available in the community, often in the form of open-source projects. However, these projects are generally self contained with little reuse between them. This paper presents a software engineering approach that intends to grant middleware independance to robotic software components so that a clear separation of concerns is achieved between highly reusable algorithmic parts and integration frameworks. Such a decoupling let middlewares be used interchangeably, while fully benefitting from their specific, individual features. This work has been integrated into a new version of the open-source G en oM component generator tool: G en oM3.

Failure of robotic software may cause catastrophic damages. In order to establish a higher level of trust in robotic systems, formal methods are often proposed. However, their applicability to the functional layer of robots remains limited because of the informal nature of specifications, their complexity and size. In this paper, we formalize the robotic framework G en oM3 and automatically translate its components to UPPAAL-SMC, a real-time statistical model checker. We apply our approach to verify properties of interest on a real-world autonomous drone navigation that does not scale with regular UPPAAL.