2 research outputs found
Continuous Relaxation of Symbolic Planner for One-Shot Imitation Learning
We address one-shot imitation learning, where the goal is to execute a
previously unseen task based on a single demonstration. While there has been
exciting progress in this direction, most of the approaches still require a few
hundred tasks for meta-training, which limits the scalability of the
approaches. Our main contribution is to formulate one-shot imitation learning
as a symbolic planning problem along with the symbol grounding problem. This
formulation disentangles the policy execution from the inter-task
generalization and leads to better data efficiency. The key technical challenge
is that the symbol grounding is prone to error with limited training data and
leads to subsequent symbolic planning failures. We address this challenge by
proposing a continuous relaxation of the discrete symbolic planner that
directly plans on the probabilistic outputs of the symbol grounding model. Our
continuous relaxation of the planner can still leverage the information
contained in the probabilistic symbol grounding and significantly improve over
the baseline planner for the one-shot imitation learning tasks without using
large training data.Comment: IROS 201
A Hybrid Architecture for Hierarchical Reinforcement Learning
Abstract Autonomous robot systems operating in the real world have to be able to learn new tasks and environmental conditions without the need for an outside teacher. While reinforcement learning represents a good formalism to achieve this, its long learning times and need for extensive exploration often make it impracticable for on-line learning on complex systems. The hybrid architecture presented in this paper addresses this issue by applying reinforcement learning on top of an automatically derived abstract Discrete Event Dynamic System (DEDS) supervisor. This reduces the problem of policy acquisition within this approach to learning to coordinate a set of closed-loop control strategies in order to perform a given task. Besides dramatically reducing the complexity of the learning task this framework also permits the incorporation of a priori knowledge and facilitates the inclusion of learned policies as actions in order to transfer skills to new task domains. To demonstrate the applicability of this approach, the architecture is used to learn locomotion gaits on a four-legged robot platform.