Multi-agent domains consisting of teams of agents that need to collaborate in an adversarial environment offer challenging research opportunities. In this article, we introduce periodic team synchronization (PTS) domains as time-critical environments in which agents act autonomously with low communication, but in which they can periodically synchronize in a full-communication setting. The two main contributions of this article are a flexible team agent structure and a method for inter-agent communication in domains with unreliable, single-channel, low-bandwidth communication. First, the novel team agent structure allows agents to capture and reason about team agreements. We achieve collaboration between agents through the introduction of formations. A formation decomposes the task space defining a set of roles. Homogeneous agents can flexibly switch roles within formations, and agents can change formations dynamically, according to pre-defined triggers to be evaluated at run-time. This flexibility increases the performance of the overall team. Our teamwork structure further includes pre-planning for frequent situations. Second, the novel communication method is designed for use during the lowcommunication periods in PTS domains. It overcomes the obstacles to inter-agent communication in multi-agent environments with unreliable, high-cost, low-bandwidth communication. We fully implemented both the flexible teamwork structure and the communication method in the domain of simulated robotic soccer, and conducted controlled empirical experiments to verify their effectiveness. In addition, our simulator team made it to the semi-finals of the RoboCup-97 competition, in which 29 teams participated.

The CMUnited-99 simulator team became the 1999 RoboCup simulator league champion by winning all 8 of its games, outscoring opponents by a combined score of 110--0. CMUnited-99 builds upon the successful CMUnited-98 implementation, but also improves upon it in many ways. This article gives a detailed presentation of CMUnited-99's improvements over CMUnited-98. 1 Introduction The CMUnited robotic soccer project is an ongoing effort concerned with the creation of collaborative and adversarial intelligent agents operating in real-time, dynamic environments. CMUnited teams have been active and successful participants in the international RoboCup (robot soccer world cup) competitions [1, 2, 16]. In particular, the CMUnited-97 simulator team made it to the semi-finals of the first RoboCup competition in Nagoya, Japan [9], the CMUnited-98 simulator team won the second RoboCup competition in Paris, France [14], and the latest CMUnited-99 simulator team won the third RoboCup competition in ...

Multi-agent domains consisting of teams of agents that need to collaborate in an adversarial environment offer challenging research opportunities. In this paper, we introduce periodic team synchronization domains, as time-critical environments in which agents act autonomously with limited communication, but they can periodically synchronize in a full-communication setting. We present a team agent structure that allows for an agent to capture and reason about team agreements. We achieve collaboration between agents through the introduction of formations. A formation decomposes the task space defininga set of roles. Homogeneous agents

This thesis describes the incremental development and main features of a synthetic multi-agent system called UvA Trilearn 2001. UvA Trilearn 2001 is a robotic soccer simulation team that consists of eleven autonomous software agents. It operates in a physical soccer simulation system called soccer server which enables teams of autonomous software agents to play a game of soccer against each other. The soccer server provides a fully distributed and real-time multi-agent environment in which teammates have to cooperate to achieve their common goal of winning the game. The simulation models many real-world complexities such as noise in object movement, noisy sensors and actuators, limited physical abilities and restricted communication. This thesis addresses the various components that make up the UvA Trilearn 2001 robotic soccer simulation team and provides an insight into the way in which these components have been (incrementally) developed. Our main contributions include a multi-threaded three-layer agent architecture, a flexible agent-environment synchronization scheme, accurate methods for object localization and velocity estimation using particle filters, a layered skills hierarchy, a scoring policy for simulated soccer agents and an e#ective team strategy. Ultimately, the thesis can be regarded as a handbook for the development of a complete robotic soccer simulation team which also contains an introduction to robotic soccer in general as well as a survey of prior research in soccer simulation. As such it provides a solid framework which can serve as a basis for future research in the field of simulated robotic soccer. Throughout the project UvA Trilearn 2001 has participated in two international robotic soccer competitions: the team reached 5th place at the German ...

We investigate teams of complete autonomous agents that can collaborate towards achieving precise objectives in an adversarial dynamic environment. We have pursued this work in the context of robotic soccer both in simulation and with real physical robots. We briefly present these two frameworks emphasizing their different technical challenges. Creating effective members of a team is a challenging research problem. We first address this issue by introducing a team architecture organization which allows for a rich task decomposition between team members. The main contribution of this paper is our introduction of an action-selection algorithm that allows for a teammate to anticipate the needs of other teammates. Anticipation is critical for maximizing the probability of successful collaboration in teams of agents. We show how our contribution applies to the two concrete robotic soccer frameworks and present controlled empirical results run in simulation. Anticipation was successfully used by both our CMUnited-98 simulator and CMUnited-98 small-robot teams in the RoboCup-98 competition. The two teams are RoboCup-98 world champions each in its own league.

In this chapter, we present the main research contributions of our champion CMUnited-98 small robot team. The team is a multiagent robotic system with global perception, and distributed cognition and action. We describe the main features of the hardware design of the physical robots, including differential drive, robust mechanical structure, and a kicking device. We briefly review the CMUnited-98 global vision processing algorithm, which is the same as the one used by the previous champion CMUnited-97 team. We introduce our new robot motion algorithm which reactively generates motion control to account for the target point, the desired robot orientation, and obstacle avoidance.

Robotic soccer is a challenging research domain which involves multiple agents that need to collaborate in an adversarial environment to achieve specific objectives. In this paper, we describe CMUnited, the team of small robotic agents that we developed to enter the RoboCup-97 competition. We designed and built the robotic agents, devised the appropriate vision algorithm, and developed and implemented algorithms for strategic collaboration between the robots in an uncertain and dynamic environment. The robots can organize themselves in formations, hold specific roles, and pursue their goals. In game situations, they have demonstrated their collaborative behaviors on multiple occasions.

Robotic soccer is a challenging research domain which involves multiple agents that need to collaborate in an adversarial environment to achieve specificobjectives. In this paper, we describe CMUnited, the team of small robotic agents that we developed to enter the RoboCup-97 competition. We designed and built the robotic agents, devised the appropriate vision algorithm, and developed and implemented algorithms for strategic collaboration between the robots in an uncertain and dynamic environment. The robots can organize themselves in formations, hold specific roles, and pursue their goals. In game situations, they have demonstrated their collaborative behaviors on multiple occasions. We present an overview of the vision processing algorithm which successfully tracks multiple moving objects and predicts trajectories. The paper then focusses on the agent behaviors ranging from low-level individual behaviors to coordinated, strategic team behaviors. CMUnited won the RoboCup-97 small-robot competition at IJCAI-97 in Nagoya, Japan.

This report describes RoboSoc, a system for developing RoboCup agents designed especially, but not only, for educational use. RoboSoc is designed to be as general, open, and easy to use as possible and to encourage and simplify the modification, extension and sharing of RoboCup agents, and parts of them. To do this I assumed four requirements from the user: she wants the best possible data, use as much time as possible for the decision making, rather act on incomplete information than not act at all, and she wants to manipulate the objects found in the soccer environment. RoboSoc consists of three parts: a library of basic objects and utilities used by the rest of the system, a basic system handling the interactions with the soccer server and the timing of the agent, and a framework for world modeling and decision support. The framework defines three concepts, views, predicates and skills. The views are specialized information processing units responsible for a specific part of the wo...

In most multiagent systems with communicating agents, the agents have the luxury of using reliable, multi-step negotiation protocols. They can do so primarily when communication is reliable and the cost of communication relative to other actions is small. Conversely, this paper considers multiagent environments with unreliable, high-cost communication. This paper presents techniques for dealing with the obstacles to inter-agent communication in such environments. A successful prototype system is fully implemented and tested in the simulated robotic soccer domain. Topic Areas: Communication languages and protocols; Organization and social structure