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Dynamic human movements are achieved by appropriate constraints on the degrees of freedom of the complex and flexible human body. The anatomy trains (ATs) theory explains such constraints with whole-body muscular connections called ATs. This paper proposes the design of a quasi-passive dynamic walker with whole-body viscoelastic connections inspired by the ATs theory and investigates the contributions of these long-distance connections to the achievement of gait. We designed a biped robot with a trunk and head, whose passive joints were supported by rubber fiber bands. The robot, named "PEARL III," is equipped with an antagonistic pair of McKibben pneumatic actuators for each leg at the human hamstring and rectus femoris positions. The most important feature of this robot is that fabric wires mechanically connect its rubber bands and actuators on the back side from the head to the foot, modeled after one of the human ATs, the superficial back lines (SBLs). In an experiment, PEARL III achieved 2D quasi-passive dynamic walking on an inclined plane by contracting and relaxing its actuators using periodic feedforward control. This result suggests that in both the robot and human cases, when a controller contracts the SBL only in the stance phase during passive dynamic walking, the SBL can achieve whole-body posture control and weight support. In addition, the SBL appears to achieve this function depending on their mode of attachment to bones and the presence or absence of antagonistic muscles (or ATs). In the future, by introducing various ATs into robots while recognizing the importance of the appropriate attachment of ATs and the presence of their antagonistic muscles (or ATs), we can expect similar effects in various 3D movements. [ABSTRACT FROM AUTHOR]

Physical human-robot interaction plays an important role in social robotics, and touch is one of the key factors that influence a human's impression of robots. However, very few studies have explored different conditions pertaining to such interactions, and therefore, only few systematic results have been reported. As the first step toward addressing this issue, we studied the types of impressions of a robot's personality that humans may experience when they touch a soft part of the robot. In the study, the left forearm of a child-like android robot named "Affetto" was exposed; the original forearm was made of silicone rubber and can be replaced with any one of three other forearms that provide different sensations of hardness upon touching. Participants were asked to touch the robot's forearm and answer evaluation questionnaires on 19 touch sensations and 46 personality impressions for each of the four conditions associated with the different forearms. Four impression factors for touch sensations and three for personality impressions were extracted from the evaluation scores by the factor analysis method. The causal relationships between these factors were analyzed by the path analysis method. Several significant causal relationships were found, for example, between preferable touch sensations and likable personality impressions. The study results are expected to help in the design of the personality impressions of robots by facilitating a more systematic design of touch sensations. Furthermore, the results of an analysis of variance suggested that the most preferable touch sensation is possibly related to the robot's appearance and that designers of social robots should understand the complex touch sensation properties of humans. [ABSTRACT FROM AUTHOR]

Child robots have been used in a lot of studies on human–robot social/physical interaction because they are suitable for safe and casual experiments. However, providing many compliant joints and lifelike exteriors to enhance their interaction potential is difficult because of the limited space available inside their bodies. In this paper, we propose an upper body structure that consists of slider crank and parallel mechanisms for linear actuators and serial mechanisms for rotary actuators. Such combinations of several joint mechanisms efficiently utilize the body space; in total, 22 degrees of freedoms were realized in an upper body space equivalent to that of an 80cm tall child. A pneumatic drive system was adopted in order to fully verify the behavioral performance of the body mechanism. The proposed redundant and compact upper body mechanism can be a platform for testing the effectiveness of future exteriors for the little child android ‘Affetto’, which was developed in order to integrate several key characteristics for achieving advanced human–robot interaction. [ABSTRACT FROM AUTHOR]