Touchless heart rate recognition by robots to support natural human-robot communication

With the proliferation of robotic assistants, such as robot vacuum cleaners, telepresence robots, or shopping assistance robots, human-robot interaction becomes increasingly more natural. The capabilities of robots are expanding, which leads to an increasing need for a natural human-robot communication and interaction. Therefore, the modalities of text- or speech-based communication have to be extended by body language and a direct feedback such as emotion or non-verbal communication. In this paper, we present a camera-based, non-body contact optical heart rate recognition method that can be used in robots in order to identify humans' reactions during a robot-human communication or interaction. For the purpose of heart rate and heart rate variability detection, we used standard cameras (webcams) that are located inside the robot's eye. Although camera-based vital sign identification has been discussed in previous research, we noticed that certain limitations with regard to real-world applications do still exist. We identified artificial light sources as one of the main influencing factors. Therefore, we propose strategies with the aim Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than the author(s) must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from of improving natural communication between social robots and humans.