EAPSI: Exploring the Unique Movement Strategy of Brittle Stars via Robotic Modeling

Clark Elizabeth G, New Haven CT

Investigators

Abstract

Brittle stars, close relatives of sea stars, are the ideal model animal for biologically inspired mobile robot design. By coordinating hundreds of moving parts, their five arms work together to permit rapid motion across the complex terrain of the sea floor. They lack a front and back, allowing them to move in every direction equally without the need to turn. When one or several arms become damaged or lost, they readjust their locomotion to compensate without any loss of movement capability. These characteristics alone make brittle stars ideal candidates for robotic imitation, yet their most striking feature is that they intercept external stimuli, make decisions, and coordinate multiple moving parts, all without a brain! Many mobile robots similarly do not rely on a single control center, although those in robots are far less complex and resilient than the biological machinery employed by brittle stars. This investigation will analyze how the brittle star nervous system controls its locomotion and engineer a robot to test the results. Thus the two major goals of the project are: 1. To determine how the brittle star nervous system works and 2. To work out how to integrate this setup into a multifaceted robotic device. Professor Akio Ishiguro and his research group at Tohoku University have engineered a variety of robots with coordinated behavior operating under decentralized control. They observe live brittle stars in the lab and incorporate their capabilities into robotic design. Through the EAPSI program and the Ishiguro Lab, this project will use this novel approach to determine how locomotion is controlled by the decentralized brittle star nervous system. This investigation will test hypotheses of sensory processing, action determination, and task delegation with a combination of experiments on live ophiuroids and mathematical and robotic modeling. This will result in a mathematical model describing the brittle star system that can be integrated into a robotic device to evaluate its accuracy and improve coordination in complex robots. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.