Title
Safe-To-Explore State Spaces: Ensuring Safe Exploration In Policy Search With Hierarchical Task Optimization
Abstract
Policy search reinforcement learning allows robots to acquire skills by themselves. However, the learning procedure is inherently unsafe as the robot has no a-priori way to predict the consequences of the exploratory actions it takes. Therefore, exploration can lead to collisions with the potential to harm the robot and/or the environment. In this work we address the safety aspect by constraining the exploration to happen in safe-to-explore state spaces. These are formed by decomposing target skills (e.g., grasping) into higher ranked sub-tasks (e.g., collision avoidance, joint limit avoidance) and lower ranked movement tasks (e.g., reaching). Sub-tasks are defined as concurrent controllers (policies) in different operational spaces together with associated Jacobians representing their joint-space mapping. Safety is ensured by only learning policies corresponding to lower ranked sub-tasks in the redundant null space of higher ranked ones. As a side benefit, learning in sub-manifolds of the state-space also facilitates sample efficiency. Reaching skills performed in simulation and grasping skills performed on a real robot validate the usefulness of the proposed approach.
Year
Venue
Field
2018
2018 IEEE-RAS 18TH INTERNATIONAL CONFERENCE ON HUMANOID ROBOTS (HUMANOIDS)
Kernel (linear algebra),Ranking,Computer science,Simulation,Harm,Collision,Human–computer interaction,Artificial intelligence,Robot,Robotics,Reinforcement learning
DocType
Volume
ISSN
Journal
abs/1810.03516
2164-0572
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Jens Lundell154.13
Robert Krug2215.59
Erik Schaffernicht321.74
Todor Stoyanov426026.07
V. Kyrki565261.79