Emotion Modelling for Social Robotics Applications: A Review

Robots of today are eager to leave constrained industrial environments and embrace unexplored and unstructured areas, for extensive applications in the real world as service and social robots. Hence, in addition to these new physical frontiers, they must face human ones, too. This implies the need to consider a human-robot interaction from the beginning of the design; the possibility for a robot to recognize users’ emotions and, in a certain way, to properly react and “behave”. This could play a fundamental role in their integration in society. However, this capability is still far from being achieved. Over the past decade, several attempts to implement automata for different applications, outside of the industry, have been pursued. But very few applications have tried to consider the emotional state of users in the behavioural model of the robot, since it raises questions such as: how should human emotions be modelled for a correct representation of their state of mind? Which sensing modalities and which classification methods could be the most feasible to obtain this desired knowledge? Furthermore, which applications are the most suitable for the robot to have such sensitivity? In this context, this paper aims to provide a general overview of recent attempts to enable robots to recognize human emotions and interact properly.