2022/12/01 by Thomas T. Zhang, Katie Kang, Zhang, Thomas T. +11 · 3 citations
Computer Science · #Domain Adaptation and Few-Shot Learning #Reinforcement Learning in Robotics #Machine Learning and Algorithms
paper · pdf · doi:10.48550/arxiv.2212.00186
We study representation learning for efficient imitation learning over linear systems. In particular, we consider a setting where learning is split into two phases: (a) a pre-training step where a shared k-dimensional representation is learned from H source policies, and (b) a target policy fine-tuning step where the learned representation is used to parameterize the policy class. We find that the imitation gap over trajectories generated by the learned target policy is bounded by O( \frack nxHNshared + \frack nuNtarget), where nx > k is the state dimension, nu is the input dimension, Nshared denotes the total amount of data collected for each policy during representation learning, and Ntarget is the amount of target task data. This result formalizes the intuition that aggregating data across related tasks to learn a representation can significantly improve the sample efficiency of learning a target task. The trends suggested by this bound are corroborated in simulation.