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Knowledge Co-Creation - Profiles of researchers

Is Emotional Interaction Possible between Humanoid Robots and Humans?

Prof. Atsuo Takanishi
School of Creative Science and Engineering
Faculty of Science and Engineering

That's the Best Part of Robotic Human Science.

I'm on the Faculty of Science and Engineering. Science is to make the unknown known. Researchers try to understand the things they do not understand, apart from using them, for example, about pi or calculus or in quantum mechanics or astrophysics. Their practical use is another thing.

In contrast, engineering serves for human well-being. Robots and other assistive devices are designed for sick or disabled people, for their convenience or to alleviate their sufferings. Engineers are thinking how to design equipment and software.

Emotion Expression Humanoid Robot WE-4R II

That does not mean, however, that science has nothing to engineering. Scientific findings, for example, theories in mathematics such as Newton's laws, have been applied to engineering. Conversely, when engineers develop a high-performance telescope, cosmologists can observe a galaxy billions of light-years away. Without engineering, scientists could not conduct cutting-edge research. And by developing robots, engineers can help people in need in terms of elderly care or advanced surgery. In that, my research gives me a great sense of satisfaction.

Meanwhile, how do we walk on two legs, by putting our heel down first, and then pushing off with the ball of our foot to take another step, while keeping the knee straight? Through demonstration experiments using robots, we can understand human motion and its mechanism from the robotics viewpoint. We are conducting scientific research while designing a humanoid robot as engineers. That's the best part of robotics, which I termed Robotic Human Science.

Off-Campus Exchange Triggers the Development of a Bipedal Humanoid Robot WABIAN-2

Unlike conventional bipedal humanoid robots such as Honda's ASIMO or HPR-2 developed by the Ministry of Economy, Trade and Industry, our WABIAN-2 can walk while keeping its knees straight due to its pelvis rotation.

I have often conducted joint research with off-campus researchers and I came up with the ideal of pelvic rotation while engaged in research on rehabilitation for disabled people. Prof. Ichiro Kato, my mentor and "the Father of robotics in Japan," who launched his research on humanoid robots at Waseda University in 1970, was also actively involved in designing prosthetic limbs and rehabilitation devices and even tutoring rehabilitation engineers as his students. One of the engineers said to me, "Why can we walk keeping knees straight? Itfs the rotation of the pelvis."

"Now I've got it!" I cried. We had assumed the pelvis did not move while walking. And we came up this idea: the pelvis is the link between the upper body and the legs and we can walk with our knees straight because the pelvis rotates in vertical and horizontal planes. In this way, we completed WABIAN-2 capable of pelvic motions.

Human-like Walking with Knee Stretched

WABIAN-2R, Capable of Walking with Knee Stretched

WABIAN-2R is capable of human-like walking with knee stretched. ASIMO and HPR walk bending their knees because they cannot stretch them for special reasons.

Theoretically, a robot can walk on two legs by controlling the body's center of gravity and acceleration and it is the bending and stretching of the knee that do control. But knee-stretching posture is called Singular Configuration, in which a calculation error occurs on the system that controls the motions of the robot, just as the case in which the denominator becomes zero. To avoid this error, we need to design a robot bending knees while walking. We have to avoid Singular Configuration.

But, when the pelvis is given rotating motion in vertical and horizontal planes, knee-stretching posture does not show Singular Configuration. Although the legs show Singular Configuration, no errors occur in calculations concerning the motions of the pelvis and consequently also in calculations concerning the motions of the entire body.

We are planning to use WABIAN-2 to evaluate walking aids and other devices developed for the elderly or people with walking disabilities.

Western Values: Is Humanoid Evil?

Meanwhile, making robots or humanoids seems to be criticized in Christian tradition: "God-made humans must not make humanoid robots." But robotics experts are downright scientific. Scuola Superiore Sant'Anna in Pisa, Italy, has a Japan-Italy joint laboratory named Robot-An, to which over 150 robotics experts come together in respect for Prof. Kato. Waseda University concluded an agreement with the university having over 500 years of history and has since continued joint research in close relationships.

In such relationships, I have got humanistic ways of thinking, for I was often asked to talk about Japanese ethics, for example, what robots are for Japanese people. I could not let Westerners say, "Japan is evil in invading the land of God's dominion with humanoids." Japanese people look on inorganic robots as if they were living but Westerners do not. For them, robots are rather considered evil, at least just tools. Elderly people in Japan would feel affection for Aibo, Sony's large dog robot, but Westerners wouldn't.

Several years ago, Steven Spielberg's 'A.I.' was released. A robot-boy is pre-programmed to love his human adoptive mother whose own sick child has been frozen until a cure can be found. Miraculously, however, the frozen child recovers and the abandoned robot-boy sets out on a journey in quest of his mother. And, several thousand years after the annihilation of mankind, the robot-boy is still in quest of his mother. The message is, human mind is susceptible to change while humanoids are considered evil but have far purer mind. Itfs a significant message for Westerners, I think.

Left Brain/Right Brain Theory: Mysterious Differences between Westerners and Japanese

I've referred to left brain/right brain theory in considering differences in perception of organic and inorganic matter and humanoids between Westerners and Japanese. The brain can be described as being divided into left and right cerebral hemispheres. While the left hemisphere is relating to language, mathematics and logics, while the right hemisphere to music, emotion, visual-spatial skills and images. Westerners receive birdsong, sound of the wind, or roar of the waves in the right hemisphere and perceive it as a noise.

In contrast, Japanese receive sound of nature in the left hemisphere and perceive it as a message. Onomatopoeia is a word that imitates the sound it is describing, such as chirp, jingle-jangle, cuckoo, and pit-a-pat. While Japanese language has 120,000 onomatopoeic words, English, among other Western languages, has 4,000 at most. I think Japanese are receiving messages of 'life' from sounds of nature.

Such differences are found having something to do with drawing no distinction between organic and inorganic matter, and with Japanese culture and mind-set. Japanese even see 'life' or a god in a rock. If your mother was declared brain death and asked to provide her heart, you would find difficulty in agreeing to that. In contrast, Westerners are rational in considering a brain-dead patient as "an organ." That's why organ transplants from brain-dead donors are being performed more frequently. That is not the case in Japan though such organ transplants were legalized ten years ago, because it is not easy for Japanese to regard a breathing, sweating brain-dead person as a corpse. That may have something to do with onomatopoeia.

A Robot Expresses Human Emotions

In reality, much further research and development will be required for robots to be practically used for our society. Especially in safety, there are many hurdles to be got over. When we can live with robots, however, our emotional affinity with robots will be another problem. We have continued joint research with Prof. Hiroshi Kimura (Waseda University School of Letters, Arts and Sciences, Psychology Major) for over ten years. Under Prof. Kimura's guidance, we have developed WE-4RII and WM-6; WE-4RII is capable to expressing human emotions like joy, anger, surprise, sadness and fear, while WM-6 is a rat-robot based on animal psychology.

While Westerners do not expect robots to have human emotions, Japanese want them more human-like. We hope that in the future we can choose our favorite robot, a robot each of us can get along well with. Japan has greater number of humanoid robots and precedent researches in robotics than any other nation does. When some Westerners are afraid of humanoids being a threat to mankind, researchers should try to arrive at a better mutual understanding, at ethical as well as technological levels.

Prof. Atsuo Takanishi & the Takanishi Laboratory website

Prof. Atsuo Takanishi
School of Creative Science and Engineering
Faculty of Science and Engineering
Waseda University

Born in Fukuoka in 1956; Doctor of Engineering; Assistant Professor/Lecturer in 1988, Associate Professor in 1990, and Professor in 1997 at Waseda University; Visiting Researcher at Massachusetts Institute of Technology in 1990-91; Visiting Professor at Scuola Superiore Sant'Anna (Italy). In winter 2000, Prof. Takanishi delivered a lecture as one of the UK's most prestigious Christmas Lectures for young people. His books include My Robot (The Yomiuri Shimbun) and Ningengata Robot no Hanashi (Humanoid Robots, The Nikken Kogyo Shimbun).

WASEDAWASEDA UNVERSITY Research Promotion Division  http://www.waseda.jp/rps/en/irp/index.html