Automatic Curriculum Learning for Developmental Machine Learners. (Génération automatique de curriculum pour apprenants artificiels)

Rémy Portelas

Abstract: A long-standing goal of Machine Learning (ML) and AI at large is to design autonomous agents able to efficiently interact with our world. Towards this, taking inspirations from the interactive nature of human and animal learning, several lines of works focused on building decision making agents embodied in real or virtual environments. In less than a decade, Deep Reinforcement Learning (DRL) established itself as one of the most powerful set of techniques to train such autonomous agents. DRL is based on the maximization of expert-defined reward functions that guide an agent’s learning towards a predefined target task or task set. In parallel, the Developmental Robotics field has been working on modelling cognitive development theories and integrating them into real or simulated robots. A core concept developed in this literature is the notion of intrinsic motivation: developmental robots explore and interact with their environment according to self-selected objectives in an open-ended learning fashion. Recently, similar ideas of self-motivation and open-ended learning started to grow within the DRL community, while the Developmental Robotics community started to consider DRL methods into their developmental systems. We propose to refer to this convergence of works as Developmental Machine Learning. Developmental ML regroups works on building embodied autonomous agents equipped with intrinsic-motivation mechanisms shaping open-ended learning trajectories. The present research aims to contribute within this emerging field. More specifically, the present research focuses on proposing and assessing the performance of a core algorithmic block of such developmental machine learners: Automatic Curriculum Learning (ACL) methods. ACL algorithms shape the learning trajectories of agents by challenging them with tasks adapted to their capacities. In recent years, they have been used to improve sample efficiency and asymptotic performance, to organize exploration, to encourage generalization or to solve sparse reward problems, among others. Despite impressive success in traditional supervised learning scenarios (e.g. image classification), large-scale and real-world applications of embodied machine learners are yet to come. The present research aims to contribute towards the creation of such agents by studying how to autonomously and efficiently scaffold them up to proficiency.