A legged robot is one of the ideal mechanisms for moving around muddy, irregular, and fragile surfaces. However, a legged robot will easily be unable to move if its body is turned over. Some robots have special mechanisms for recovery. But having extra mechanisms may increase possibilities of malfunction. Our approach is to make a robot that has legs around its body so that it never turns over. Also our idea is to drive these legs synchronously by a set of gears and links so that it performs the same gait to the same moving direction. We found that this is possible for any prismatic bodies that have side surfaces of a multiple of four. In this paper we demonstrate this by some examples of four side surfaces configurations.

This paper proposes a foot shape design to enhance stability of passive dynamic walk, by constraining fall down phenomenon in both sagittal and lateral planes. We focus on the over swinging situation for a passive dynamic biped walker, where exceeding sideway and forward swing of a leg causes fall down phenomenon. From geometrical analysis, we found that stability under a wide range of slope inclinations will be achieved by limiting swing legs spatially in a certain angle. We also found that the limiting leg's angles are achieved by a certain type of a 3D sole shape, which provides stability in a compact size. In lateral plane, limiting swing from side to side is effective to avoid falling down in this plane. This is realized by preparing limiter shape in lateral direction, such as two separate sub-foots placed apart in parallel. In sagittal plane, stability of walk is kept by constraining fall down phenomenon toward moving direction, by a sharp edge at the head of a foot. A prototype of a foot that realizes these two constraining effects in a 3D sole shape design is proposed. We show that the constraining effect by the proposed foot shape is effective for a walk comparing to an arctic foot shape.

The Robot World Cup Initiative (RoboCup) is an international joint project to promote science and technology in intelligent robotics, AI and related fields with the specific goal of building a fully humanoid robot that can be the human world cup champion by 2050, and to apply technologies developed in this activity to socially significant issues such as rescue, and for next generation industries. This idea inspired the imagination of people and it has grown to be one of the largest research areas in multi-agent robotics. The paper discusses extension of RoboCup activity for education and edutainment. Specifically, RoboCup has initiated a new project called RoboCup Jr. that aims at promotion of engineering education and popularization of robotics using RoboCup. A RoboCup Jr. league will be created to meet diverse needs of the education field, and a series of organizational frameworks are proposed to develop a network of social, personal, educational, and technical infrastructures to assist those who are interested in RoboCup Jr. activity.

RoboCup is an increasingly successful attempt to promote the full integration of robotics and AI research. The most prominent feature of RoboCup is that it provides the researchers with the opportunity to demonstrate their research results as a form of competition in a dynamically changing hostile environment, defined as the international standard game definition, in which the gamut of intelligent robotics research issues are naturally involved. The article describes what we have learned from the past RoboCup activities, and overview the future perspectives of RoboCup in the next century, mainly focusing on the real robot leagues. Finally, we introduce the new leagues, one of which will have been held at RoboCup-99 in Stockholm.

We report the result on RoboCup-97. RoboCup97 is the first RoboCup [1] competition which is held at IJCAI-97. RoboCup-97 consists on three leagues: simulation league. small-size real robot league and middlesize real robot league. The simulator (called Soccer Server) (see Fig.1) is designed and implemented by Noda[2]. The field of small-size league is a ping pong table. The field of middle-size league is 9 (3× 3) ping pong tables. The lists of the participants are as follows.

Collision avoidance is an essential problem for applications of multiple mobile robots. The authors have proposed new sensor system called LOCISS (Locally Communicable Infrared Sensory System) to detect robots and obstacles using infrared local communication. Robots mounting LOCISS can exchange useful information for collision avoidance such as speed and moving direction. In this paper, a set of rules for collision avoidance among multiple autonomous mobile robots using LOCISS is proposed. Each robot mutually carries out collision avoidance using the proposed rule. The validity of this set of rules is shown through a series of experiments using mobile robots.

This paper presents an approach we have recently developed for multi-robot cooperation. It is based on a paradigm where robots incrementally merge their plans into a set of already coordinated plans. This is done through exchange of information about their current state and their future actions. This leads to a generic framework which can be applied to a variety of tasks and applications. The paradigm, called plan-merging paradigm, is presented and illustrated through its application to planning, execution and control of a large fleet of a autonomous mobile robots for load transport tasks in a structured environment.

Distributed autonomous robotic systems which are composed of multiple robotic agents have been attracted the attention of many researchers as a new strategy for flexible and robust robotic systems. For cooperative multiple mobile robots in distributed autonomous robotic systems, recognition of the dynamic environment is required. In this paper, a new sensory system with local communication functionality is developed utilizing infra-red devices. Based on the discussion on sensing and communication for cooperative multiple mobile robots, requirements for the sensory system are derived. Then, the infra-red sensory system is designed and developed taking account of the required function. This system enables not only detection of collisions against obstacles or other robots but also local communication between robots. This system can also detect interference of plural infra-red signals. Finally the developed system as introduced, and its performance obtained as a results of experiments is shown.