  Emotions are the intrinsic or extrinsic representations of our experiences.
The importance of emotions during a human-human interaction is immense as it
formulates the basis of our interaction framework. There are several approaches
in psychology to evaluate emotional states in humans based on the perceived
stimuli. However, the topic has been less explored as far as human-robot
interaction is concerned. This paper uses an appropriate emotion appraisal
mechanism from psychology, generating an emotional state in a humanoid robot
on-the-fly during human-robot interaction. Since the exhibition of only six
basic emotions is not sufficient to cater to diverse situations, the use of the
Circumplex Model in this work has allowed the life-sized robot called ROBIN to
experience 28 emotional states in different interaction scenarios. Realistic
robot behaviour has been generated based on the proposed appraisal system in
various interaction scenarios.
