Intelligent robot companions contribute significantly in improving living standards in the modern society. Therefore, human-like decision making skills are sought after during the design of such robots. On the one hand, such features enable the robot to be easily handled by its non-expert human user. On the other hand, the robot will have the capability of dealing with humans without causing any disturbance by the robot's behavior. Mimicing human emotional intelligence is one of the best and reasonable ways of laying the foundation for robotic emotional intelligence. As robots are widely deployed in social environments, perception of the situation or intentions of a user prior to an interaction is required to be proactive. Proactive robots are required to understand what is communicated by the human body language prior to approaching a human. Social constraints in an interaction could be demolished by this assessment in this regard. In this review, we incorporate various findings of human-robot interaction, social robotics and psychophysiology to assess intelligent systems which were capable of evaluating the emotional state of humans prior to an interaction. Second, we identify the cues and evaluation techniques that were utilized by such intelligent agents to simulate and evaluate the suitability of a proactive interaction. Available literature has been evaluated to distinguish limitations of existing methods and suggest possible improvements. These limitations, guiding principles to be adhered to and suggested improvements, are presented as an outcome of the review.
INDEX TERMSInteraction initiation, nonverbal cues, context-awareness, social robots, human-robot interaction. A. G. BUDDHIKA P. JAYASEKARA (M'07-SM'17) received the B.Sc. and M.Sc. degrees in electrical engineering from the University of Moratuwa, respectively, in 2004 and 2006, and the doctoral degree in robotics and intelligent systems from Saga University, Japan. He received the Japanese Government Monbukagakusho Scholarship to pursue postgraduate studies in Japan. He joined the Department of Electrical Engineering, University of Moratuwa, after completing his doctoral studies in 2010, where he currently a Senior Lecturer.His main research interests include artificial intelligence techniques, human-robot interaction, human-friendly robotics, machine learning, and intelligent systems. He is the Principle Investigator of the Intelligent Service Robotics Group, Department of Electrical Engineering, University of Moratuwa, and working as the Director of Center for Advanced Robotics (CAR), a multidisciplinary research center of University of Moratuwa from 2017. Currently, he is working on two main projects: intelligent mobile robot for domestic environments (MIRob-Moratuwa Intelligent Robot) and intelligent wheelchair for domestic environments. D. P. CHANDIMA (M'03-SM'17) received the B.Sc. degree from the