IMLE Policy: Fast and Sample Efficient Visuomotor Policy Learning via Implicit Maximum Likelihood Estimation

TL;DR

IMLE Policy introduces a data-efficient, fast, and simple imitation learning method for visuomotor tasks that outperforms existing approaches in low-data and real-time scenarios.

Contribution

The paper presents IMLE Policy, a novel behaviour cloning approach that achieves high performance with less data and faster inference by using implicit maximum likelihood estimation.

Findings

Requires 38% less data than baselines.

Improves inference speed by 97.3% over diffusion policies.

Effectively learns complex multi-modal behaviors in robotics.

Abstract

Recent advances in imitation learning, particularly using generative modelling techniques like diffusion, have enabled policies to capture complex multi-modal action distributions. However, these methods often require large datasets and multiple inference steps for action generation, posing challenges in robotics where the cost for data collection is high and computation resources are limited. To address this, we introduce IMLE Policy, a novel behaviour cloning approach based on Implicit Maximum Likelihood Estimation (IMLE). IMLE Policy excels in low-data regimes, effectively learning from minimal demonstrations and requiring 38\% less data on average to match the performance of baseline methods in learning complex multi-modal behaviours. Its simple generator-based architecture enables single-step action generation, improving inference speed by 97.3\% compared to Diffusion Policy, while outperforming single-step Flow Matching. We validate our approach across diverse manipulation tasks in simulated and real-world environments, showcasing its ability to capture complex behaviours under data constraints. Videos and code are provided on our project page: https://imle-policy.github.io/.