Susumu Tachi

Susumu Tachi (舘 暲, Tachi Susumu; born January 1, 1946) is Professor Emeritus of the University of Tokyo, Founding President of the Virtual Reality Society of Japan, and Founding Chairman of Telexistence Inc.^[1]

Dr. Tachi received the B.E., M.S., and Ph.D. degrees in mathematical engineering and information physics from the University of Tokyo in 1968, 1970, and 1973, respectively.

He joined the Faculty of Engineering of the University of Tokyo in 1973, and in 1975 moved to the Mechanical Engineering Laboratory, Ministry of International Trade and Industry, Tsukuba Science City, Japan, where he served as the Director of the Biorobotics Division. From 1979 to 1980, Dr. Tachi was a Japanese Government Award Senior Visiting Scientist at the Massachusetts Institute of Technology, Cambridge, USA, and in 1988 he served as Chairman of the IMEKO (International Measurement Confederation) Technical Committee on Measurement in Robotics.^[2] In 1989 he rejoined the University of Tokyo, and served as a Professor at the Department of Information Physics and Computing until March 2009. In April 2009, he moved to Keio University, where he served as a Professor at the Graduate School of Media Design and the Director of the International Virtual Reality Center until March 2015. From April 2015 to March 2020, he conducted the JST ACCEL "Embodied Media" research project at the Tachi Laboratory, Institute of Gerontology, the University of Tokyo, as Research Director. In January 2017, he founded and became Chairman of Telexistence Inc. Prof. Tachi was conferred the title of Professor Emeritus of the University of Tokyo in June 2009.^[1]

One of his early scientific achievements is the invention (1975) and development of an intelligent mobile robot system for the blind called the Guide Dog Robot (1976-1983), which was the first of its kind. This system is known as MELDOG.^[3]

In 1980, Dr. Tachi invented the concept of telexistence, which enables a highly realistic sense of existence in a remote place without any actual travel, and has been working on the realization of telexistence since then.^[4]

Telexistence became the fundamental guiding principle of the eight-year Japanese National Large-Scale Project, “Advanced Robot Technology in Hazardous Environments” (1983-1990). Through this project, he conducted theoretical studies, established systematic design procedures, developed experimental hardware telexistence systems such as TELESAR, and demonstrated the feasibility of the concept.^[4]

His present research covers telexistence, real-time remote robotics (R-Cubed), and virtual reality.^[5] Key examples of his research in these areas include:

• TELESAR (TELExistence Surrogate Anthropomorphic Robot) series: This series represents the history of "telexistence"—a technology that allows a human to control a robot remotely and feel as if they are actually present in that remote environment. Key models include: TELESAR I (Proof of Concept; world's first anthropomorphic telexistence experiment);^[6] TELESAR II (Mutual Telexistence using RPT);^[7] TELESAR IV (Mobile + Mutual);^[8] TELESAR V (Haptic Primary Color Transmission);^[9] and TELESAR VI (67-DOF Full Avatar with 10-finger haptics).^[10]
• Retro-reflective Projection Technology: A technology that integrates information with an object using retro-reflective materials. By projecting images onto the object's surface, it can be made to appear transparent or to have a different texture. It is applied in technologies such as optical camouflage,^[11] transparent cockpits,^[12] and mutual telexistence.^[13]
• Haptic Primary Colors: A proposal of a fundamental principle for haptics that aims to reproduce diverse tactile sensations by decomposing and synthesizing haptic information into fundamental elements, similar to the three primary colors of light.^[14]
• Autostereoscopic VR: Research and development of VR technology based on new principles that allow users to experience stereoscopic images without special goggles. Prime examples include TWISTER,^[15] which uses a rotating barrier method; HaptoMirage,^[16] which uses a virtual shutter glass method; and Repro3D,^[17] which uses a retro-reflective projection method.

• The most influential person in Tachi's early life and the one who directed him toward intellectual inquiry was his maternal grandfather. His grandfather was the nephew of Sankichi Sato, the first Japanese Professor of Surgery at the University of Tokyo (formerly Tokyo Imperial University). Because Tachi's great-grandfather died young, his grandfather was taken in by his great-grandfather's younger brother, Sankichi Sato, and grew up in a profoundly academic atmosphere. This academic environment was carried on in his grandfather's home, where the young Tachi grew up hearing stories of Sankichi Sato countless times.^[18]
• In the summer of 1965, a little over a year after entering the University of Tokyo, Tachi was undecided on his field of study as the application deadline approached. He was leaning towards physics but also had a vague interest in people and a desire to do research involving them. It was then that a reading of Norbert Wiener's “The Human Use of Human Beings” was broadcast from a radio he happened to turn on. He recalls that as soon as he heard it, a feeling “like being struck by lightning” ran through his whole body. He immediately rushed to the General Library of the University of Tokyo to find Wiener’s books and became deeply engrossed in reading them. This experience convinced him to devote himself to cybernetics research. As a result, he decided to pursue that field and proceeded to the Department of Mathematical Engineering and Information Physics within the Faculty of Engineering, the University of Tokyo, the only place he could study cybernetics at the time.^[18][19][20]
• His second son is Tomohiro Tachi, an origami engineering researcher and a professor at the University of Tokyo.^[21]
• In 1991, Tachi founded the International Conference on Artificial Reality and Telexistence (ICAT) and hosted its inaugural meeting in Japan in July of that year. As the world’s first international conference dedicated to virtual reality, ICAT attracted numerous prominent researchers and startup CEOs from abroad, despite being held in Japan. At the time, virtual reality was still in its infancy—not only exploring potential for societal and industrial applications, but also striving to establish itself as an academic discipline. ICAT is now recognized as the longest-running international conference in the field of virtual reality^[22].
• In 1993, he founded the International-collegiate Virtual Reality Contest (IVRC) with the goal of popularizing VR among students and fostering young researchers. This student VR contest (now known as Interverse Virtual Reality Challenge) has since produced numerous individuals who are active across various fields – including many researchers and engineers in VR and human augmentation (embodied science), as well as artists, entrepreneurs, and industry leaders.^[23]
• In 1996, Tachi spearheaded the establishment of the Virtual Reality Society of Japan (VRSJ), recognizing the need for a dedicated academic platform to advance virtual reality research. By advocating for its importance and rallying support from fellow researchers, he laid the groundwork for the society and was subsequently appointed its first president. The founding vision of the VRSJ was to formalize virtual reality as an academic discipline and to foster dialogue and collaboration across diverse fields. Today, the society plays a central role in the academic community and continues to contribute to the development and dissemination of virtual reality studies in Japan and beyond^[24].
• In 2004, Tachi initiated the “Cybernetics Society” (サイバネティクス研究会) with the aim of directly passing down the philosophy of "science and technology for humans to live in a human way," which he considers the essence of cybernetics. This Cybernetic Society serves as a community of researchers dedicated to human augmentation and related fields. Currently, over 80 Ph.D. holders are members of this society.^[25]

Prof. Tachi is also a founding director of the Robotics Society of Japan (RSJ), a fellow of the Society of Instrument and Control Engineers (SICE) and is the founding president of the Virtual Reality Society of Japan (VRSJ). See also his work on cloaking technology.(link to video on YouTube)

• "Susumu Tachi - Tachilab". tachilab.org.
• "Tachi Laboratory". tachilab.org.
• "Telexistence". tachilab.org.
• "Guide Dog Robot MELDOG". tachilab.org.
• "Virtual Reality". tachilab.org.
• "Tachilab Youtube". youtube.com.
• "Google Scholar - Susumu Tachi". scholar.google.com.