  Emotions can provide a natural communication modality to complement the
existing multi-modal capabilities of social robots, such as text and speech, in
many domains. We conducted three online studies with 112, 223, and 151
participants to investigate the benefits of using emotions as a communication
modality for Search And Rescue (SAR) robots. In the first experiment, we
investigated the feasibility of conveying information related to SAR situations
through robots' emotions, resulting in mappings from SAR situations to
emotions. The second study used Affect Control Theory as an alternative method
for deriving such mappings. This method is more flexible, e.g. allows for such
mappings to be adjusted for different emotion sets and different robots. In the
third experiment, we created affective expressions for an
appearance-constrained outdoor field research robot using LEDs as an expressive
channel. Using these affective expressions in a variety of simulated SAR
situations, we evaluated the effect of these expressions on participants'
(adopting the role of rescue workers) situational awareness. Our results and
proposed methodologies provide (a) insights on how emotions could help
conveying messages in the context of SAR, and (b) evidence on the effectiveness
of adding emotions as a communication modality in a (simulated) SAR
communication context.
