Citation: Matsumaru, T. Methods of
Generating Emotional Movements
and Methods of Transmitting
Behavioral Intentions: A Perspective
on Human-Coexistence Robots.
Sensors 2022, 22, 4587. https://
doi.org/10.3390/s22124587
Academic Editors: Abolfazl Zaraki
and Hamed Rahimi Nohooji
Received: 25 May 2022
Accepted: 16 June 2022
Published: 17 June 2022
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Perspective
Methods of Generating Emotional Movements and Methods of
Transmitting Behavioral Intentions: A Perspective on
Human-Coexistence Robots
Takafumi Matsumaru
Graduate School of Information, Production and Systems (IPS), Waseda University, Kitakyushu 808-0135, Japan;
matsumaru@waseda.jp
Abstract:
The purpose of this paper is to introduce and discuss the following two functions that are
considered to be important in human-coexistence robots and human-symbiotic robots: the method
of generating emotional movements, and the method of transmitting behavioral intentions. The
generation of emotional movements is to design the bodily movements of robots so that humans can
feel specific emotions. Specifically, the application of Laban movement analysis, the development
from the circumplex model of affect, and the imitation of human movements are discussed. However,
a general technique has not yet been established to modify any robot movement so that it contains
a specific emotion. The transmission of behavioral intentions is about allowing the surrounding
humans to understand the behavioral intentions of robots. Specifically, informative motions in arm
manipulation and the transmission of the movement intentions of robots are discussed. In the former,
the target position in the reaching motion, the physical characteristics in the handover motion, and
the landing distance in the throwing motion are examined, but there are still few research cases. In
the latter, no groundbreaking method has been proposed that is fundamentally different from earlier
studies. Further research and development are expected in the near future.
Keywords:
human-coexistence robot; human-symbiotic robot; emotional movement; forthcoming
movement; behavioral intention; embodiment; bodily movement; informative motion; preliminary
motion; preparatory motion
1. Introduction
The purpose of this paper is to introduce and discuss the following two functions
that are considered to be important in human-coexistence robots and human-symbiotic
robots: the method of generating emotional movements, and the method of transmitting
behavioral intentions.
The most prominent feature of robots is that they have a body as an entity, and by
moving that body, it is useful and beneficial to humans. Additionally, the main function
of robots is to realize physical work by physical interaction with the environment using
their bodily movements. In this paper, the function of transmitting emotional effects
and behavioral intentions, i.e., the internal information of the robot, to humans using the
bodily movements of robots is discussed. One solution to the problem of improving the
affinity and friendliness felt by humans in human-coexistence robots is to design the robot
movements so that humans can perceive the emotions and intentions of the robot.
In this paper, examples of major research and development are introduced and dis-
cussed. Here, we focus on when original ideas were first presented and new concepts
were first proposed, regardless of whether they were published in academic journals or
international conferences. Despite the important issues identified, we found that there are
not many new methods, distinctive approaches, or interesting ideas. This also shows that
the performance of the functions realized so far is still insufficient, that is, there is a lot of
room for future research and development.
Sensors 2022, 22, 4587. https://doi.org/10.3390/s22124587 https://www.mdpi.com/journal/sensors
