Morphological Development in Robotic Learning: A Survey

Humans and animals undergo morphological development (MD) processes from infancy to adulthood that have been shown to facilitate learning. However, most of the work on developmental robotics (DRs) considers fixed morphologies, addressing only the development of the cognitive system of the robots. This article aims to provide a survey of the work that is being carried out within the relatively new field of MD in robots. In particular, it contemplates MD as the changes that occur in the properties of the joints, links and sensors of a robot during its lifetime and focuses on the work carried out by different authors to try to determine their influence on robot learning. To this end, walking, reaching, grasping and vocalization have been identified as the four most representative tasks addressed in the field, clustering the work of the different authors around them. The approach followed is multidisciplinary, discussing the relationships among DRs, embodied artificial intelligence and developmental psychology in humans in general, as well as for each of the tasks, and providing an overview of the many avenues of research that are still open in this field.