An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of observing the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement -- determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, we investigate the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. In other research, analytical techniques have been developed for solving this problem in complex geometrical environments. However, these previous approaches are very computationally expensive - at least exponential in the number of robots -- and cannot be implemented on robots operating in real-time. Thus, this paper reports on our studies of a simpler problem involving uncluttered environments -- those with either no obstacles or with randomly distributed simple convex obstacles. We focus primarily on developing the on-line distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. This paper first formalizes the problem (which we term CMOMMT for Cooperative Multi-Robot Observation of Multiple Moving Targets) and discusses related work. We then present a distributed heuristic approach (which we call A-CMOMMT) for solving the CMOMMT problem that uses weighted local force vector control. We analyze the effectiveness of the resulting weighted force vector approach by comparing it to three other approaches. We present the results of our experiments in...

We present a field study of police SWAT teams for the purpose of enabling grounded design of a system to coordinate distributed field robots. The mission-oriented, spatially distributed SWAT environment provides a rich resource for robotics designers that mirrors field robot deployments in key ways. We highlight the processes with which SWAT team leaders create and maintain common ground among team members and coordinate action in these tightly-coupled, distributed teams. We present a system for coordinating distributed robots that we designed based on our SWAT team observations.

In recent years there has been a great interest in robot software control architectures. However, although many interesting solutions have been presented, most of the research tackled problems related to single robots perceiving, navigating and acting in common environments. Instead, most of the practical applications of mobile robotics for service tasks in civilian environments consist of systems composed of multiple robots communicating with each other, with external sensing and actuating devices, and with external supervising workstations. For these reasons and thanks to the progress in communication technology, research issues in autonomous robot architectures have to be addressed also taking into account this multi-agent notion of robot autonomy. In this sense, the RoboCup competition offers a great opportunity to address this problem because the software architecture of a robot soccer player must allow a successful intra-robot integration of the different activities (visual perception, path planning, strategy planning, motion control, etc.) spanning over many different types of representation (raw sensor data, images, symbolic plans, etc.). Moreover the architecture must also guarantee a successful inter-robot integration by supporting communication and co-operation.

. This paper presents our design philosophy for robotic teams involved in distributed exploratory missions, such as military reconnaissance, scientific exploration, and security patrols. It outlines the fundamental requirements of these mission types, finds commonalities among them, analyzes the roles robots can play, and notes research areas requiring greater attention. Key Words: Robotic exploration, Heterogeneous robot teams 1 Introduction We define exploratory missions as those missions in which the primary goal is to gather information about some structure, environment, region, individual, or group. Some manipulation of the environment to aid in information gathering may occur (such as drilling a core sample) but modification of the environment is not in itself a goal of an exploratory mission. Similarly, exploration may be facilitated by the movement of resources (such as positioning a recharging station in the vicinity of the exploration site) but movement of resources is, li...

Introduction We are pursuing a bottom-up exploration of the evolution of behaviours involving collective locomotion of numerous miniature autonomous mobile robots. Collective locomotion is a subset of collective robotics [Bonabeau & Theraulaz 94] which focuses on the specific tasks required to move a group of autonomous agents (e.g. mobile virtual or physical robots) from an origin to a destination. It deals with topics such as navigation, distributed path planning, inter-individual communication, co-operation, auto-organisation, robustness, etc. Our work is influenced by concepts such as distributed autonomous robotic systems : each robot interacts only with neighbours (within a limited range) and operates on its own, without external supervision [Asama 94]. We reject centralised control systems, since they have multiple restrictions and drawbacks, considered unacceptable for realworld robotics : in such systems, a supervisor needs to communicate permanently with each individ

This thesis describes the mechatronics design of a cooperative multi-robot system, including systems level design, practical implementation, and testing. Two main subjects are integrated in this research work: the generic concept of a Robot Society as an engineering framework to control an autonomously operating distributed multi-robot system, and the constructed prototype society consisting of several sensor/actuator robots for submerged use in a liquid environment. These novel types of prototype robots, SUBMARs, are targeted for distributed autonomous perception and task execution in the internal, three-dimensional on-line monitoring of various flow-through processes. The Robot Society control architecture implemented into SUBMAR robots supports such features as the autonomous cooperation of the robots, multi-tasking, self-organization, and selfoptimization in task execution. The mechatronics design of the robots has followed a minimalist approach, where the structure of the robot is maximally simplified. As a solution to compensate the obvious limitations derived from minimalism, the

Abstract—This paper describes a human-robot interaction that uses dialogues as a basis for the operation of multiple robots in space construction. The dialogues, which are conducted by the operator and a community of software agents, consist of explicit and implicit queries and responses regarding the state of the robots and their environment. A dialogue enables a high-level but active role for the operator in resource management and task planning for space construction missions with multiple robots. The dynamic nature of such a scenario will be challenging for the operator, but a dialogue interaction provides valid, upto-date information about robot capabilities that make up the tools that the operator may use to solve problems creatively. This interaction enables the management of large teams of

: This paper presents a new approach to the observation and the control of the behavior of multiple autonomous robots. It is the microscopic observation expressed by dynamic equations that has been commonly employed to observe the multi-robot behavior. However, the approach has the difficulties in estimating the behavior and the mutual interactions of robots. Furthermore, it is hard to realize the system by checking up all the factors of the system. It seems that a macroscopic observation defined by state equations is efficient for recognizing the multiple robots behavior. Therefore, we would like to propose a quantitative observation approach. This attempt means the application of the thermodynamic macroscopic state values to the multi-robot systems. The advantage of this approach is that it enables us to observe the behavior of autonomous robots in real world by mapping the characteristic values of them in another conceptual state space. First, we discuss the implication of applying ...

Abstract not found

Multi-robot systems of autonomous mobile robots offer many benefits but also many challenges. This work addresses collision avoidance of robots solving continuous problems in known environments. The approach to handling collision avoidance is here to enhance a motion planning method for single-robot systems to account for auxiliary robots. A few assumptions are made to put the focus of the work on path planning, rather than on localization. A method, based on exact cell decomposition and extended with a few rules, was developed and its consistency was proven. The method is divided into two steps: path planning, which is off-line, and path monitoring, which is on-line. This work also introduces the notion of path obstacle, an essential tool for this kind of path planning with many robots. Furthermore, an implementation was performed on a system of omni-directional robots and tested in simulations and experiments. The implementation practices centralized control, by letting an additional computer handle the motion planning, to relieve the robots of strenuous computations. A few drawbacks with the method are stressed, and the characteristics of problems that the method is suitable for are presented.