Special Robotics Seminar
Title: Topological Robotic Mechanism Design
Speaker: Kenjiro TADAKUMA, Associate Professor, Graduate School of Information Sciences (GSIS), Tohoku University
Date: March 21
Time: 11:00 AM - 12:00 PM
Location: MERL 203
Conventional omnidirectional wheel mechanisms are limited in their ability to climb steps and cross gaps. The Omni-Ball, consisting of two connected hemispherical wheels, overcomes these limitations by enabling the crossing of higher obstacles and larger gaps than previously. By elongating the Omni-Ball longitudinally into a cylinder shape, we obtained the Omni-Crawler, which enables omnidirectional mobility on rough terrain. In addition, transforming the cylinder shape into a torus with inner-outer membrane motion not only enables robotic mobility in murky water, but makes it possible to further transition from Omni-Crawler to Omni-Gripper. Conventional soft grippers are not suitable for objects with sharp sections such as broken valves and glass shards, but the torus shape solves this problem by using a three-layered variable stiffness skin-bag made of cut-resistant cloth. A similar function could also be achieved using a string of beads made of titanium which can grip objects of almost any shape, even when they are on fire. To build on these gripper mechanisms from the viewpoint of bioinspired robotics and "homeomorphic mechanism design," we also developed a structure inspired from the proboscis (mouthpart) of Nemertea, also known as the ribbon worm, and combined it with self-healing materials to realize a robotic blood vessel with active self-healing properties. Through the addition of repair mechanisms, we expect it to be possible to achieve the active transformation of one’s own body, thereby creating the ultimate robotic mechanism.
Kenjiro Tadakuma holds an Associate Professorship at Tohoku University in the field of robotics, where he has been leading the Plus Ultra Mechanism Group since 2015. Throughout his career, he has made outstanding contributions to the design of novel robotic mechanisms. As a Ph.D. student at Tokyo Tech (2004 – 2007), he invented the first omnidirectional mechanism, known as “Omni-Ball”. This brought him to MIT’s Field and Space Robotics laboratory as a post-doctoral researcher (2007), where he went on to contribute to the Mars hopper project and developed a polymer-based mechanical device for medical applications. Back in Japan, he held positions at Tohoku University, the University of Electro-Communications, and Osaka University (2008 – 2015), where he expanded on the concept of omnidirectional mechanisms with successful applications in mobile robotics and gripping mechanisms, such as the “Omni-Crawler” and “Omni-Gripper”. At Tohoku University, he is further aiming to extract the essence of biological mechanisms to express them as robotic mechanisms. Notably, his team won the IEEE ICRA Best Paper Award on Mechanisms and Design in 2019. The nature of his inventions illustrates his deep focus in pioneering the field of robotics mechanisms as a fundamental science.