ORIGINAL ARTICLE T.D. Ngo (*) Center for Embedded Software Systems CISS, Aalborg University, Fr. Bajersvej 7B, 9220 Aalborg East, Denmark Tel. +45-9635-7515; Fax +45-9635-0510 e-mail: dungnt@cs.aau.dk H. Raposo · H. Schiøler Control and Automation, Aalborg University, Aalborg, Denmark This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007 Artif Life Robotics (2008) 12:47–52 © ISAROB 2008 DOI 10.1007/s10015-007-0440-1 Trung Dung Ngo · Hector Raposo · Henrik Schiøler Multiagent robotics: toward energy autonomy goals that are difficult to achieve by an individual agent or monolithic system. 1 The general model of a MAS is consti- tuted by four elements: Agents, the Environment, the Inter- actions between the agent and the environment, and the Organization of the agents in a specific environment. MAS A E I O = + + + Basically, in a MAS there is no centralized control: infor- mation is distributed, computation is asynchronous, and therefore no agent is completely capable of solving a problem [8]. A robot needs assistance from other agents to solve its own problem, or must help other agents with their problem, as appropriate. The adaptiveness of an agent depends on the characteristics of such an agent, its sur- rounding environment, its capabilities of interaction with other agents or environments, and its organization capabili- ties in a network. Therefore, in mapping a MAS to a multi- robot system, an autonomous robot is able to function as an autonomous agent in the MAS: a robotic agent. On the other hand, a robotic agent is aware of itself as a physical robot, in fact, the robot exists if it is capable of acquiring an energy resource. In this paper, we propose a multiagent robotic system with two types of agent: the mother charging station and the mobile robot. The mother charging station agent is to recharge all empty energy cells that are carried to the station, and supply refreshed energy cells to the mobile robotic agents when they arrive. The mobile robotic agent is equipped with a special energy exchange mechanism, so it is capable not only of collecting and carrying energy cells, e.g., rechargeable batteries at the charging station to power its functions, but also of sharing energy cells with others if demanded. We briefly describe our models of single robotic agents and their coordination in Sect. 2. In Sect. 3, we perform our simulation of robotic agent behavior under the constraints of their remaining energy and relative distances. We imple- ment the simulation in accordance with agent characteris- tics, interaction, organization, and change of environment in order to suggest a course for our real multirobot implemen- tation. The paper is concluded in Sect. 4. Abstract In this paper, we propose a novel trend in multia- gent robotics: energy autonomy. A definition of energy autonomy is developed from an original concept, “potential energy,” that is under the constraints of remaining energy capacity and the relative distance among robotic agents. Toward energy autonomy, we initially present a simulation of a multiagent robotic system in which each robot is capable of exchanging energy cells with other robots. Our simula- tion points out that: (1) each robot is able not only to act as an autonomous agent, but also to interact with others to be beyond the individual capabilities; (2) in order to adapt to changes in the environment, each robot is situated as an adaptive agent in a network of neighboring robots, which leads to a state of energy autonomy. Finally, based on the results of the simulation, we adjust the rules for our real multirobot system. Key words Energy autonomy · Potential energy · multiagent-Robotics · Self-sufficient energy 1 Introduction A multiagent system (MAS) is a system composed of a number of agents that are collectively capable of reaching Received and accepted: May 28, 2007