DEVELOPMENT OF AN INDICATION DEVICE FOR THE ACTION INTENTION OF A TWO-WHEELED DIFFERENTIAL DRIVE ROBOT IN AN ENVIRONMENT WHERE IT PASSES BY PEDESTRIANS

The two-wheel differential drive type is widely used in mobile robots, which can efficiently perform accurate speed adjustment and quick course changes through the rotational difference between the two wheels on either side. It is difficult to guess how such a mobile robot will move from its appearance. Therefore, they may cause collisions with pedestrians when traveling in urban areas in the future. In this paper, we propose the development of a new device for indication of the mobile robot\u27s intention to action for passing pedestrians. RGB LED strip lights were employed as the action intention indicator. By emitting light from the RGB LED strip lights mounted around the vehicle body, the mobile robot indicates its action to passing pedestrians. In order to determine an effective method of indicating the action to passing pedestrians, we conducted a two-stage evaluation in a scenario in which the vehicle was passing a pedestrian. In the first stage, we evaluated the validity of the system by conducting a reaction time and action comprehension experiment on 12 subjects. In the second stage, we evaluated the power consumption of the action intention indicator device, and finally determined the proposed action intention indicator method for the mobile robot

Coordinating Joint Action in a Real-Life Activity: The Interplay of Explicit and Implicit Coordination

Humans engage in joint actions on a daily basis. Some of these joint actions are explicitly coordinated using, for example, speech and gesture, and the others are implicitly coordinated with the actions themselves. The first chapter of this dissertation reviews the use of speech, gesture, and intentional behavioral signals in explicit coordination of joint action and identifies three cognitive mechanisms that enable implicit coordination of joint action, namely, motor resonance, joint intentionality, and environmental and social affordance. The second chapter reports an empirical study exploring the employment of explicit and implicit coordination of joint action in a complex real-life joint activity, assembling a TV cart from its parts. We coded the content of the utterances and gestures that pairs of participants used throughout the assembly and the major and subordinate joint actions they performed. We then coded how each joint action was coordinated, that is, using speech, gestures, or action itself. The results showed speech and gesture served primarily to establish and sustain a shared mental model of the environmental affordances between the co-actors, which occurred primarily at the beginning of the task and as the participants began to attach two major parts. For both major and subordinate joint actions alike, the specifics of the joint actions such as the goal and division of labor was primarily coordinated implicitly. We argue that the shared mental model scaffolded the participants’ implicit coordination of the actions. These findings provide evidence that action itself is a communicative device and part of the conversation between co-actors of a joint activity. They also lend support to the argument that joint action cannot be fully understood on the individual level but must be interpreted as a collective of which each individual is a part