New reactive behaviors that implement formations in multirobot teams are presented and evaluated. The formation behaviors are integrated with other navigational behaviors to enable a robotic team to reach navigational goals, avoid hazards and simultaneously remain in formation. The behaviors are implemented in simulation, on robots in the laboratory and aboard DARPA's HMMWV-based unmanned ground vehicles. The technique has been integrated with the autonomous robot architecture (AuRA) and the UGV Demo II architecture. The results demonstrate the value of various types of formations in autonomous, human-led and communications-restricted applications, and their appropriateness in different types of task environments.

Behavior-based formation control for multirobot teams

There has been increased research interest in systems composed of multiple autonomous mobile robots exhibiting cooperative behavior. Groups of mobile robots are constructed, with an aim to studying such issues as group architecture, resource conflict, origin of cooperation, learning, and geometric problems. As yet, few applications of cooperative robotics have been reported, and supporting theory is still in its formative stages. In this paper, we give a critical survey of existing works and discuss open problems in this field, emphasizing the various theoretical issues that arise in the study of cooperative robotics. We describe the intellectual heritages that have guided early research, as well as possible additions to the set of existing motivations.

Cooperative mobile robotics: antecedents and directions

 Four appendices summarize valuable resources available for the reader: Appendix A contains printed and recorded resources, Appendix B suggests web-related resources, Appendix C discusses GP software tools, including Discipulus, the GP software developed by the authors, and Appendix D mentions events most closely related to the field of genetic programming. URLs can be found online at http://mkp.com/GPIntro.

Genetic Programming: An Introduction

In this paper we present a novel method for creating realistic, controllable motion. Given a corpus of motion capture data, we automatically construct a directed graph called a motion graph that encapsulates connections among the database. The motion graph consists both of pieces of original motion and automatically generated transitions. Motion can be generated simply by building walks on the graph. We present a general framework for extracting particular graph walks that meet a user's specifications. We then show how this framework can be applied to the specific problem of generating different styles of locomotion along arbitrary paths.

Motion graphs

[서평]「Component Software」 - Beyond Object-Oriented Programming -

This paper describes algorithms for the animation of male and female models performing three dynamic athletic behaviors: running, bicycling, and vaulting. We animate these behaviors using control algorithms that cause a physically realistic model to perform the desired maneuver. For example, control algorithms allow the simulated humans to maintain balance while moving their arms, to run or bicycle at a variety of speeds, and to perform two vaults. For each simulation, we compare the computed motion to that of humans performing similar maneuvers. We perform the comparison both qualitatively through real and simulated video images and quantitatively through simulated and biomechanical data.

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Animating human athletics

Animated characters can play the role of teachers or guides, team mates or competitors, or just provide a source of interesting motion in virtual environments. Characters in a compelling virtual environment must have a variety of complex and interesting behaviors, and be responsive to the user's actions. The difficulty of constructing such synthetic characters currently hinders the development of these environments, particularly when realism is required. The authors present one approach to populating virtual environments-using dynamic simulation to generate the motion of characters. They explore this approach's effectiveness with two virtual environments: the border collie environment, in which the user acts as a border collie to herd robots into a corral, and the Olympic bicycle race environment, in which the user participates in a bicycle race with synthetic competitors.

Dynamically simulated characters in virtual environments

Birds, fish, and many other animals travel as a flock, school, or herd. Animals in these groups must remain in close proximity while avoiding collisions with neighbors and with obstacles. We would like to reproduce this behavior for groups of simulated creatures traveling fast enough that dynamics plays a significant role in determining their movement. In this paper, we describe an algorithm for controlling the movements of creatures that travel as a group and evaluate the performance of the algorithm with three simulated systems: legged robots, humanlike bicycle riders, and point-mass systems. Both the legged robots and the bicyclists are dynamic simulations that must control balance, facing direction, and forward speed as well as position within the group. The simpler point-mass systems are included because they help us to understand the effects of the dynamics on the performance of the algorithm.

Group Behaviors for Systems with Significant Dynamics

Pedestrian navigation is a complex function of human dynamics, a desired destination, and the presence of obstacles. People cannot stop and start instantaneously and their turning abilities are influenced by kinematic and dynamical constraints. A realistic model of human walking paths is an important development for entertainment applications and many classes of simulations. We present a novel behavioral model of path planning that extends previous models through its significant use of pedestrian performance statistics that were obtained during a suite of experiments. We develop an original interpretation of quantitative metrics for measuring a model's accuracy, and use it to compare our path planning approach to a popular contemporary method. Results indicate that this new path planning model better fits natural human behavior than previous models.

Realistic human walking paths

Diamond Park is a social virtual reality system in which multiple geographically separated users can speak to each other and participate in joint activities. The central theme of the park is cycling. Human visitors to the park are represented by 3D animated avatars and can explore a square mile of 3D terrain. In addition to human visitors, the park hosts a number of computer simulations, including tour buses and autonomous animated figures. Diamond Park is implemented using a software platform called Spline, which makes it easy to build virtual worlds where multiple people interact with each other and with computer simulations in a 3D visual and audio environment. Spline performs all the processing necessary to maintain a distributed, modifiable, and extendable model of a virtual world that is shared between the participants. For more information visit http://www.merl.com.

David C. Brogan

Papers

Animating human athletics

Dynamically simulated characters in virtual environments

Group Behaviors for Systems with Significant Dynamics

Realistic human walking paths

Diamond park and spline: Social virtual reality with 3d animation, spoken interaction, and runtime extendability