Abstract— This paper presents an exploratory behavioral model for human–robot communication based on an ethological approach. To maintain long-term human–robot communication, building social relationships between the user and robot is important. As a model of social relationships between different species, we focus on human– dog relationships. We apply dogs’ behaviors observed from the stranger situation test as a base model of the robot. Exploratory behavior is one of the dogs’ behaviors. In this paper, human–robot communication is considered for the purpose of home-care support. For this purpose, an exploratory behavior model for home-care applications is proposed. Keywords- human–robot communication; social robotics; ethology; home-care application; intelligent space I. INTRODUCTION Intelligent environments are being studied to support and enhance human activities. In some such studies, the subjects are observed using distributed networked sensors, human activities are observed, and services are provided using distributed actuators such as displays and mobile robots. To observe a dynamic environment, many intelligent devices, called distributed intelligent network devices (DINDs), are placed in an intelligent environment, such as that shown in Fig. 1. We named this type of space an Intelligent Space (iSpace). A DIND, which is a basic iSpace element, consists of three basic components: sensors, processors, and network devices. Communicating with individual DINDs enables an iSpace to apprehend and understand events occurring within the space, and to activate intelligent agents such as mobile robots, computer devices, and digital equipment to provide information and services to users based on the observed information [1]-[4]. An iSpace can obtain the positions of more than one person at the same time, even if these persons are in different locations within the space. This research was supported by Chuo University Joint Research Grant, and JSPS-HAS joint research program. Ryuichi Numakunai, Takuya Ichikawa, and Mihoko Niitsuma are with Department of Precision Mechanics, Chuo University, 1-13-27 Kasuga, Bunkyo-Ku, Tokyo 112-8551, Japan. (email: niitsuma@mech.chuo-u.ac.jp). Peter Korondi is with Budapest University of Technology and Economics, Budapest, Hungary. Hideki Hashimoto is with Department of Electrical, Electronic and Communication Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-Ku, Tokyo 112-8551, Japan. Márta Gácsi is with Department of Ethology Eötvös Loránd University, Budapest, Hungary. Figure 1. iSpace concept A monitoring system is necessary to reduce the amount of attention and care required by care assistants and nurses for maintaining the safety of the elderly in their care. We therefore use iSpace to monitor a daily environment for the purpose of home-care support. To apply iSpace to a support system for monitoring the elderly, after detecting an event in the environment, iSpace needs to inform the situation to the caregivers without disturbing their primary activities. Since a caregiver usually moves within a space, the information should be presentable at any location within this space. Mobility is required for a physical agent of iSpace. We therefore use a mobile robot to provide monitoring information to a care assistant. Robots have been used to deliver information services to users within a wide range of applications, for example, daily information delivery [5], a cooking support system [6], and to guide robots in a museum [7]-[9]. A study on a cooking support system has suggested that robot behaviors are particularly useful for presenting location information to users. A robot is also useful in increasing the pleasure derived from cooking. The robot behaves on the basis of the user’s cooking method. In the case of an information- delivery robot [5], the robot was evaluated through comparison with a computer display. The experiment showed that, compared to a display, users felt a sense of emotional attachment to the robot, and even attended to it. Accordingly, we consider robot behavior a useful and effective way to deliver information to users. A robot behavioral model, however, depends on the user applications. When we consider a robot to be used continuously over a long period of time, relationship building between users and the robot becomes more important. A robot is required to behave appropriately to build social relationships with its users. The robot is also required to behave autonomously based on the current situation within the working space to present the monitoring results. We Exploratoryl Behavior in Ethologically Inspired Robot Behavioral Model Ryuichi Numakunai, Takuya Ichikawa, Márta Gácsi, Peter Korondi, Senior Member, IEEE, Hideki Hashimoto, Fellow, IEEE, Mihoko Niitsuma, Member, IEEE 2012 IEEE RO-MAN: The 21st IEEE International Symposium on Robot and Human Interactive Communication. September 9-13, 2012. Paris, France. 978-1-4673-4605-4/12/$31.00 ©2012 IEEE 577