Don't Start from Scratch: Behavioral Refinement via Interpolant-based Policy Diffusion

Fuente: arXiv
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Auteurs principaux: Chen, Kaiqi, Lim, Eugene, Lin, Kelvin, Chen, Yiyang, Soh, Harold
Format: Preprint
Publié: 2024
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author Chen, Kaiqi
Lim, Eugene
Lin, Kelvin
Chen, Yiyang
Soh, Harold
author_facet Chen, Kaiqi
Lim, Eugene
Lin, Kelvin
Chen, Yiyang
Soh, Harold
contents Imitation learning empowers artificial agents to mimic behavior by learning from demonstrations. Recently, diffusion models, which have the ability to model high-dimensional and multimodal distributions, have shown impressive performance on imitation learning tasks. These models learn to shape a policy by diffusing actions (or states) from standard Gaussian noise. However, the target policy to be learned is often significantly different from Gaussian and this mismatch can result in poor performance when using a small number of diffusion steps (to improve inference speed) and under limited data. The key idea in this work is that initiating from a more informative source than Gaussian enables diffusion methods to mitigate the above limitations. We contribute both theoretical results, a new method, and empirical findings that show the benefits of using an informative source policy. Our method, which we call BRIDGER, leverages the stochastic interpolants framework to bridge arbitrary policies, thus enabling a flexible approach towards imitation learning. It generalizes prior work in that standard Gaussians can still be applied, but other source policies can be used if available. In experiments on challenging simulation benchmarks and on real robots, BRIDGER outperforms state-of-the-art diffusion policies. We provide further analysis on design considerations when applying BRIDGER. Code for BRIDGER is available at https://github.com/clear-nus/bridger.
format Preprint
id arxiv_https___arxiv_org_abs_2402_16075
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Don't Start from Scratch: Behavioral Refinement via Interpolant-based Policy Diffusion
Chen, Kaiqi
Lim, Eugene
Lin, Kelvin
Chen, Yiyang
Soh, Harold
Machine Learning
Artificial Intelligence
Robotics
Imitation learning empowers artificial agents to mimic behavior by learning from demonstrations. Recently, diffusion models, which have the ability to model high-dimensional and multimodal distributions, have shown impressive performance on imitation learning tasks. These models learn to shape a policy by diffusing actions (or states) from standard Gaussian noise. However, the target policy to be learned is often significantly different from Gaussian and this mismatch can result in poor performance when using a small number of diffusion steps (to improve inference speed) and under limited data. The key idea in this work is that initiating from a more informative source than Gaussian enables diffusion methods to mitigate the above limitations. We contribute both theoretical results, a new method, and empirical findings that show the benefits of using an informative source policy. Our method, which we call BRIDGER, leverages the stochastic interpolants framework to bridge arbitrary policies, thus enabling a flexible approach towards imitation learning. It generalizes prior work in that standard Gaussians can still be applied, but other source policies can be used if available. In experiments on challenging simulation benchmarks and on real robots, BRIDGER outperforms state-of-the-art diffusion policies. We provide further analysis on design considerations when applying BRIDGER. Code for BRIDGER is available at https://github.com/clear-nus/bridger.
title Don't Start from Scratch: Behavioral Refinement via Interpolant-based Policy Diffusion
topic Machine Learning
Artificial Intelligence
Robotics
url https://arxiv.org/abs/2402.16075