Distributed control diffusion: towards a flexible programming paradigm for modular robots

ABSTRACT

A self-reconfigurable robot is a robotic device that can change its own shape. Self-reconfigurable robots are commonly built from multiple identical modules that can manipulate each other to change the shape of the robot. The robot can also perform tasks such as locomotion without changing shape. Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular, self-reconfigurable robots, we present the concept of distributed control diffusion: distributed queries are used to identify modules that play a specific role in the robot, and behaviors that implement specific control strategies are diffused throughout the robot based on these role assignments. This approach allows the programmer to dynamically distribute behaviors throughout a robot and moreover provides a partial abstraction over the concrete physical shape of the robot.

We have implemented a prototype of a distributed control diffusion system for the ATRON modular, self-reconfigurable robot. The prototype relies on a simple virtual machine with a dedicated instruction set, allowing mobile programs to migrate between the modules that constitute a robot. Through a number of simulated experiments, we should how a single rule-based controller program implemented using distributed control diffusion can perform simple obstacle avoidance in a wide range of different car-like robots constructed using ATRON modules.

REFERENCES

• 1: D. Brandt and E. H. Ostergaard. Behaviour subdivision and generalization of rules in rule based control of the ATRON self-reconfigurable robot. In Proceeding of the International Symposium on Robotics and Automation (ISRA), pages 67--74, Queretaro, Mexico, September 2004.
• 2: R. Brooks. A robust layered control system for a mobile robot. IEEE Journal of Robotics and Automation, 2:14--23, March 1986.
• 3: Z. Butler, K. Kotay, D. Rus, and K. Tomita. Generic decentralized control for a class of self-reconfigurable robots. In Proceedings, IEEE International Conference on Robotics and Automation (ICRA'02), pages 809--815, Washington, DC, USA, 2002. IEEE Press.
• 4: A. Castano and P. Will. Autonomous and self-sufficient conro modules for reconfigurable robots. In Proceedings of the 5th International Symposium on Distributed Autonomous Robotic Systems (DARS), pages 155--164, Knoxville, Texas, USA, 2000.
• 5: D. J. Christensen and K. Støy. Selecting a meta-module to shape-change the ATRON self-reconfigurable robot. In Proceedings of IEEE International Conference on Robotics and Automations (ICRA), pages 2532--2538, Orlando, USA, May 2006.
• 6: Nicolai Dvinge, Ulrik P. Schultz, and David Christensen. Roles and self-reconfigurable robots, in Proceedings of the ^2nd Workshop on Roles and Relationships in Object Oriented Programming, Multiagent Systems, and Ontologies Workshop (co-located with ECOOP 2007 Berlin). Technical Report 2007-9, Technical University of Berlin, 2007.
• 7: T. Fukuda and S. Nakagawa. Method of autonomous approach, docking and detaching between cells for dynamically reconfigurable robotic system CEBOT. JSME International Journal, 33(2):263--268, 1990.
• 8: Chalermek Intanagonwiwat , Ramesh Govindan , Deborah Estrin, Directed diffusion: a scalable and robust communication paradigm for sensor networks, Proceedings of the 6th annual international conference on Mobile computing and networking, p.56-67, August 06-11, 2000, Boston, Massachusetts, United States [doi>10.1145/345910.345920]
• 9: Chalermek Intanagonwiwat , Ramesh Govindan , Deborah Estrin , John Heidemann , Fabio Silva, Directed diffusion for wireless sensor networking, IEEE/ACM Transactions on Networking (TON), v.11 n.1, p.2-16, February 2003 [doi>10.1109/TNET.2002.808417]
• 10: M. W. Jorgensen, E. H. Ostergaard, and H. H. Lund. Modular ATRON: Modules for a self-reconfigurable robot. In Proceedings of IEEE/RSJ International Conference on Robots and Systems (IROS), pages 2068--2073, Sendai, Japan, September 2004.
• 11: H. H. Lund, R. Beck, and L. Dalgaard. Self-reconfigurable robots with ATRON modules. In Proceedings of 3rd International Symposium on Autonomous Minirobots for Research and Edutainment (AMiRE 2005), Fukui, 2005. Springer-Verlag.
• 12: S. Murata, E. Yoshida, K. Tomita, H. Kurokawa, A. Kamimura, and S. Kokaji. Hardware design of modular robotic system. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 2210--2217, Takamatsu, Japan, 2000.
• 13: Esben H. Ostergaard. Efficient distributed "hormone" graph gradients. In Proceedings of Nineteenth International Joint Conference on Artificial Intelligence (IJCAI), pages 1489--1495, Edinburgh, Scotland, July 2005.
• 14: Esben H. Ostergaard and Henrik H. Lund. Distributed cluster walk for the atron self-reconfigurable robot. In Proceedings of the The 8th Conference on Intelligent Autonomous Systems (IAS-8), pages 291--298, Amsterdam, Holland, March 2004.
• 15: Daniela Rus , Marsette Vona, Crystalline Robots: Self-Reconfiguration with Compressible Unit Modules, Autonomous Robots, v.10 n.1, p.107-124, January 2001 [doi>10.1023/A:1026504804984]
• 16: U. Schultz, K. Støy, N. Dvinge, and D. Christensen. Sensor networks and self-reconfigurable robots, October 2006. Position paper at the OOPSLA'06 Workshop on Building Software for Sensor Networks.
• 17: U. P. Schultz, D. Christensen, and K. Støy. A domain-specific language for programming self-reconfigurable robots, October 2007. Accepted at the APGES'07 Workshop (co-located with GPCE 2007 Salzburg).
• 18: W.-M. Shen, M. Krivokon, H. Chiu, J. Everist, M. Rubenstein, and J. Venkatesh. Multimode locomotion via superbot robots. In Proceedings of the 2006 IEEE International Conference on Robotics and Automation, pages 2552--2557, Orlando, FL, 2006.
• 19: Wei-Min Shen , Yimin Lu , Peter Will, Hormone-based control for self-reconfigurable robots, Proceedings of the fourth international conference on Autonomous agents, p.1-8, June 03-07, 2000, Barcelona, Spain [doi>10.1145/336595.336602]
• 20: Kasper Stoy, Wei-Min Shen, and Peter Will. Using role based control to produce locomotion in chain-type self-reconfigurable robots. IEEE Transactions on Robotics and Automation, special issue on self-reconfigurable robots, 2002.
• 21: K. Støy. How to construct dense objects with self-reconfigurable robots. In Proceedings of European Robotics Symposium (EUROS), pages 27--37, Palermo, Italy, May 2006.
• 22: K. Støy, W.-M. Shen, and P. Will. Implementing configuration dependent gaits in a self-reconfigurable robot. In Proceedings of the 2003 IEEE international conference on robotics and automation (ICRA'03), pages 3828--3833, Tai-Pei, Taiwan, September 2003.
• 23: M. Yim, D. Duff, and K. Roufas. Polybot: A modular reconfigurable robot. In Proceedings of the IEEE International Conference on Robotics and Automation (ICRA), pages 514--520, San Francisco, CA, USA, 2000.
• 24: Y. Zhang, K. Roufas, and M. Yim. Software architecture for modular self-reconfigurable robots. In IEEE/RSJ International Conference on Intelligent Robots and Systems, Hawaii, 2001.
• 25: Y. Zhang, M. Yim, K. Roufas, and C. Eldershaw. Attribute/service model: Design patterns for distributed coordination of sensors, actuators and tasks. In Workshop on Embedded Systems Codesign, 2002.