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Anurag Ajay

16 accepted papers

2024

Learning Multimodal Behaviors from Scratch with Diffusion Policy Gradient

NeurIPS 2024poster

Deep reinforcement learning (RL) algorithms typically parameterize the policy as a deep network that outputs either a deterministic action or a stochastic one modeled as a Gaussian distribution, hence restricting learning to a single behavioral mode. Meanwhile, diffusion models emerged as a powerful…

2024

OpenEQA: Embodied Question Answering in the Era of Foundation Models

CVPR 2024poster

We present a modern formulation of Embodied Question Answering (EQA) as the task of understanding an environment well enough to answer questions about it in natural language. An agent can achieve such an understanding by either drawing upon episodic memory exemplified by agents on smart glasses or b…

Cited by 118SourcePDFScholar
2023

Compositional Foundation Models for Hierarchical Planning

NeurIPS 2023poster

To make effective decisions in novel environments with long-horizon goals, it is crucial to engage in hierarchical reasoning across spatial and temporal scales. This entails planning abstract subgoal sequences, visually reasoning about the underlying plans, and executing actions in accordance with t…

Cited by 45SourcePDFScholar
2023

Is Conditional Generative Modeling all you need for Decision Making?

ICLR 2023top-5%

Recent improvements in conditional generative modeling have made it possible to generate high-quality images from language descriptions alone. We investigate whether these methods can directly address the problem of sequential decision-making. We view decision-making not through the lens of reinforc…

Cited by 413SourcePDFScholar
2023

Parallel $Q$-Learning: Scaling Off-policy Reinforcement Learning under Massively Parallel Simulation

ICML 2023poster

Reinforcement learning is time-consuming for complex tasks due to the need for large amounts of training data. Recent advances in GPU-based simulation, such as Isaac Gym, have sped up data collection thousands of times on a commodity GPU. Most prior works have used on-policy methods like PPO due to…

2023

Statistical Learning under Heterogenous Distribution Shift

ICML 2023poster

This paper studies the prediction of a target $\mathbf{z}$ from a pair of random variables $(\mathbf{x},\mathbf{y})$, where the ground-truth predictor is additive $\mathbb{E}[\mathbf{z} \mid \mathbf{x},\mathbf{y}] = f_\star(\mathbf{x}) +g_{\star}(\mathbf{y})$. We study the performance of empirical r…

Cited by 7SourcePDFScholar
2022

Distributionally Adaptive Meta Reinforcement Learning

NeurIPS 2022accept

Meta-reinforcement learning algorithms provide a data-driven way to acquire policies that quickly adapt to many tasks with varying rewards or dynamics functions. However, learned meta-policies are often effective only on the exact task distribution on which they were trained and struggle in the pres…

Cited by 19SourcePDFScholar
2021

OPAL: Offline Primitive Discovery for Accelerating Offline Reinforcement Learning

ICLR 2021poster

Reinforcement learning (RL) has achieved impressive performance in a variety of online settings in which an agent’s ability to query the environment for transitions and rewards is effectively unlimited. However, in many practical applications, the situation is reversed: an agent may have access to…

Cited by 209SourcePDFScholar
2020

Long-Horizon Prediction and Uncertainty Propagation with Residual Point Contact Learners

ICRA 2020poster

The ability to simulate and predict the outcome of contacts is paramount to the successful execution of many robotic tasks. Simulators are powerful tools for the design of robots and their behaviors, yet the discrepancy between their predictions and observed data limit their usability. In this paper…

Cited by 14SourceScholar
2019

Combining Physical Simulators and Object-Based Networks for Control

ICRA 2019poster

Physics engines play an important role in robot planning and control; however, many real-world control problems involve complex contact dynamics that cannot be characterized analytically. Most physics engines therefore employ approximations that lead to a loss in precision. In this paper, we propose…

Cited by 69SourceScholar
2019

Learning to Navigate Endoscopic Capsule Robots

RA-L 2019

Deep reinforcement learning (DRL) techniques have been successful in several domains, such as physical simulations, computer games, and simulated robotic tasks, yet the transfer of these successful learning concepts from simulations into the real world scenarios remains still a challenge. In this le

Cited by 28SourceScholar
2018

Augmenting Physical Simulators with Stochastic Neural Networks: Case Study of Planar Pushing and Bouncing

IROS 2018poster

An efficient, generalizable physical simulator with universal uncertainty estimates has wide applications in robot state estimation, planning, and control. In this paper, we build such a simulator for two scenarios, planar pushing and ball bouncing, by augmenting an analytical rigid-body simulator w…

Cited by 154SourceScholar
2017

Reset-free guided policy search: Efficient deep reinforcement learning with stochastic initial states

ICRA 2017poster

Autonomous learning of robotic skills can allow general-purpose robots to learn wide behavioral repertoires without extensive manual engineering. However, robotic skill learning must typically make trade-offs to enable practical real-world learning, such as requiring manually designed policy or valu…

Cited by 40SourceScholar
2016

Backprop KF: Learning Discriminative Deterministic State Estimators

NeurIPS 2016poster

Generative state estimators based on probabilistic filters and smoothers are one of the most popular classes of state estimators for robots and autonomous vehicles. However, generative models have limited capacity to handle rich sensory observations, such as camera images, since they must model the…

Cited by 267SourcePDFScholar