Danfei Xu

I am an Assistant Professor at the School of Interactive Computing at Georgia Tech and a (part-time) Research Scientist at NVIDIA AI. I work at the intersection of Robotics and Machine Learning.

I received my Ph.D. in CS from Stanford University advised by Fei-Fei Li and Silvio Savarese (2015-2021) and B.S. from Columbia University (SEAS'15). I've spent time at DeepMind UK (2019), ZOOX (2017), Autodesk Research (2016), CMU RI (2014), and Columbia Robotics Lab (2013-2015).

Research opportunities: Please fill out this questionnaire and email me once submitted.
We especially encourage applications from students of traditionally underrepresented groups in robotics and AI such as BIPOC (black, indigenous, and people of color), women, and LGBTQ+ communities.

Email  /  Google Scholar  /  CV (July 2022)  /  Github  /  Twitter

Research

We aim to build general-purpose and adaptable "brains" for robots in home, factory, healthcare, and search & rescue missions alike. Our work focuses on endowing robots with both flexible high-level planning abilities ("what to do next") and robust low-level sensorimotor control ("how to do it"). The research draws equally from Robotics and Machine Learning, with the following themes:

  • Compositionality: Inspired by human's ability to "make infinite use of finite means", we aim to enable (good!) combinatorial explosions in robots' ability to solve new tasks. Examples include neural program synthesis for control [a][b], compositional diffusion models for planning [a], and learning neural-symbolic motor skills [a].
  • Generative Modeling: Modeling complex, high-dimensional distributions is fundamental to many robotics problems. We aim to advance core generative modeling research and their applications to robotics problems. Examples include modeling human behaviors in human-robot collaboration [a][b], modeling dynamics in manipulation planning [a], and explorative "play" behaviors [a][b].
  • Data-centric Robot Learning: While many AI domains have achieved remarkable success with large-scale learning, Robotics is critically limited in data scale and coverage. Our work develop systems and algorithms for data collection [a], generation [a], quality control [a], as well as standard datasets and benchmarks [a].
  • Full-stack Robot Learning: Robotics is as much science as system building. We are committed to developing high-quality, open-source robot hardware and software systems to demonstrate and promote "full-stack" progress in learning-based robotics. We actively maintain Robomimic, a general-purpose Robot Learning framework and benchmark.

The Research Group

I direct the Robot Learning and Reasoning Lab (RL2) at Georgia Tech. The current members are:

Alumni:
News
Teaching
Publications and Preprints (representative works are highlighted)
Generative Factor Chaining: Coordinated Manipulation with Diffusion-based Factor Graph
Utkarsh Mishra, Yongxin Chen, Danfei Xu
In Submission

A compositional generative model that can plan for long-horizon, complex coordinated manipulation tasks.

Legibility Diffuser: Offline Imitation for Intent Expressive Motion
Matthew Bronars, Shuo Cheng, Danfei Xu
In Submission

Learning to generate legible robot motion (motion with expressive intent) with Conditional Diffusion Models.

Neural Visibility Field for Uncertainty-Driven Active Mapping
Shangjie Xue, Jesse Dill, Pranay Mathur, Frank Dellaert, Panagiotis Tsiotras, Danfei Xu
CVPR 2024

A principled Bayesian framework to model uncertainty in NeRF for active mapping.

NOD-TAMP: Multi-Step Manipulation Planning with Neural Object Descriptors
Shuo Cheng, Caelan Garrett, Ajay Mandlekar, Danfei Xu
Arxiv

Solving multi-step manipulation problems with zero-shot generalization.

EmerNeRF: Emergent Spatial-Temporal Scene Decomposition via Self-Supervision
Jiawei Yang, Boris Ivanovic, Or Litany, Xinshuo Weng, Seung Wook Kim, Boyi Li, Tong Che, Danfei Xu, Sanja Fidler, Marco Pavone, Yue Wang
ICLR 2024

Unsupervised 4D representation learning from videos.

C3DM: Constrained-Context Conditional Diffusion Models for Imitation Learning
Vaibhav Saxena, Yotto Koga, Danfei Xu
Arxiv

High-precision manipulation with generative action modeling.

Generative Skill Chaining: Long-Horizon Skill Planning with Diffusion Models
Utkarsh Mishra, Shangjie Xue, Yongxin Chen, Danfei Xu
CoRL 2023

[website]

A new algorithm to chain together skill-level diffusion models to solve long-horizon manipulation tasks.

Neural Field Dynamics Model for Granular Object Piles Manipulation
Shangjie Xue, Shuo Cheng, Pujith Kachana, Danfei Xu
CoRL 2023
ICRA'23 Workshop on Representing and Manipulating Deformable Objects (Best Paper finalist)

[website]

A new field-based representation (occupancy density) to model and optimize granular object manipulation.

Learning to Discern: Imitating Heterogeneous Human Demonstrations with Preference and Representation Learning
Sachit Kuhar, Shuo Cheng, Shivang Chopra, Matthew Bronars, Danfei Xu
CoRL 2023

An offline imitation learning algorithm to learn from mixed-quality human demonstrations.

Human-in-the-Loop Task and Motion Planning for Imitation Learning
Ajay Mandlekar*, Caelan Garret*, Danfei Xu, Dieter Fox
CoRL 2023

[website]

We present HITL-TAMP, a system that merges human teleoperation with automated TAMP to efficiently train robots for complex tasks.

Language-Guided Traffic Simulation via Scene-Level Diffusion
Ziyuan Zhong, Davis Rempe, Yuxiao Chen, Boris Ivanovic, Yulong Cao, Danfei Xu, Marco Pavone, Baishakhi Ray
CoRL 2023 (Oral)

GPT4-guided trajectory diffusion model.

MimicPlay: Long-Horizon Imitation Learning by Watching Human Play
Chen Wang, Linxi Fan, Jiankai Sun, Ruohan Zhang, Li Fei-Fei, Danfei Xu, Yuke Zhu, Anima Anandkumar
CoRL 2023 (Best Paper and Best Systems Paper Finalist)

We leverage human video data to train a planner to guide robust low-level task execution.

Guided Skill Learning and Abstraction for Long-Horizon Manipulation
Shuo Cheng, Danfei Xu
Robotics and Automation Letters (RA-L) 2023
CoRL'22 LHP Workshop (Best Paper finalist)

We use Task and Motion Planning (TAMP) as guidance for learning generalizable and composable sensorimotor skills.

ProgPrompt: Generating Situated Robot Task Plans using Large Language Models
Ishika Singh, Valts Blukis, Arsalan Mousavian, Ankit Goyal, Danfei Xu, Jonathan Tremblay, Dieter Fox, Jesse Thomason, Animesh Garg
ICRA 2023

We harness the power of large language model to generate program-like task plans.

BITS: Bi-level Imitation for Traffic Simulation
Danfei Xu*, Yuxiao Chen*, Boris Ivanovic, Marco Pavone
ICRA 2023

Hierarchical imitation for generating diverse, realistic, and robust traffic behaviors.

Guided Conditional Diffusion for Controllable Traffic Simulation
Ziyuan Zhong, Davis Rempe, Danfei Xu, Yuxiao Chen, Sushant Veer, Tong Che, Baishakhi Ray, Marco Pavone
ICRA 2023

Learn behavior prior through diffusion-based imitation. Sample desired behaviors by conditional diffusion and Signal-Temporal Logic (STL) rules.

Robust Trajectory Prediction against Adversarial Attacks
Yulong Cao, Danfei Xu, Xinshuo Weng, Zhuoqing Mao, Anima Anandkumar, Chaowei Xiao, Marco Pavone
CoRL 2022 (Oral)

Defending against attacks that target generative behavior models.

AdvDO: Realistic Adversarial Attacks for Trajectory Prediction
Yulong Cao, Chaowei Xiao, Anima Anandkumar, Danfei Xu, Marco Pavone
ECCV 2022

Physically-plausible attack on behavior forecasting models.

Generalizable Task Planning through Representation Pretraining
Chen Wang, Danfei Xu, Li Fei-Fei
Robotics and Automation Letters (RA-L) 2022

Building generalizable world models for planning with unseen objects and environments.

What Matters in Learning from Offline Human Demonstrations for Robot Manipulation
Ajay Mandlekar, Danfei Xu, Josiah Wong, Soroush Nasiriany, Chen Wang, Rohun Kulkarni, Li Fei-Fei, Silvio Savarese, Yuke Zhu, Roberto Martin-Martin
CoRL 2021 (Oral)

[code+dataset][website][blogpost]

A large-scale study on learning manipulation skills from human demonstrations.

Human-in-the-Loop Imitation Learning using Remote Teleoperation
Ajay Mandlekar, Danfei Xu, Roberto Martin-Martin, Yuke Zhu, Li Fei-Fei, Silvio Savarese
Arxiv Preprint, 2021

Human-in-the-loop learning for complex manipulation tasks.

Co-GAIL: Learning Diverse Strategies for Human-Robot Collaboration
Chen Wang, Claudia D'Arpino, Danfei Xu, Li Fei-Fei, Karen Liu, Silvio Savarese
CoRL 2021

Learning human-robot collaboration policies from human-human collaboration demonstrations.

Generalization Through Hand-Eye Coordination: An Action Space for Learning Spatially-Invariant Visuomotor Control
Chen Wang*, Rui Wang*, Ajay Mandlekar, Li Fei-Fei, Silvio Savarese, Danfei Xu
IROS 2021

An learnable action space for recovering human's hand-eye coordination behaviors by learning from human demonstrations.

Deep Affordance Foresight: Planning Through What Can Be Done in the Future
Danfei Xu, Ajay Mandlekar, Roberto Martin-Martin, Yuke Zhu, Silvio Savarese, Li Fei-Fei
(Long version) ICRA 2021
(Short version) Oral Presentation, NeurIPS Workshop on Object Representations for Learning and Reasoning, 2020

We extend the classical definition of affordance to enable generalizable long-horizon planning.

Positive-Unlabeled Reward Learning
Danfei Xu, Misha Denil
(Long version) CoRL 2020
(Short version) Late-Breaking Paper, NeurIPS Deep Reinforcement Learning Workshop 2019

[Video]

An algorithm framework that simultaneously addresses the reward delusion problem in supervised reward learning and the overfitting discriminator problem in adversarial imitation learning.

Procedure Planning in Instructional Videos
Chien-Yi Chang, De-An Huang, Danfei Xu, Ehsan Adeli, Li Fei-Fei
Juan Carlos Niebles
ECCV, 2020

Learning to plan from instructional videos.

Learning to Generalize Across Long-Horizon Tasks from Human Demonstrations
Ajay Mandlekar*, Danfei Xu*, Roberto Martin-Martin, Silvio Savarese, Li Fei-Fei
RSS, 2020

[website] [video] [blog post]

Learning visuomotor policies that can generalize across long-horizon tasks by modeling latent compositional structures.

6-PACK: Category-level 6D Pose Tracker with Anchor-Based Keypoints
Chen Wang, Roberto Martin-Martin, Danfei Xu, Jun Lv, Cewu Lu, Li Fei-Fei, Silvio Savarese, Yuke Zhu
ICRA, 2020

[website] [video] [code]

Real-time category-level 6D object tracking from RGB-D data.

Regression Planning Networks
Danfei Xu, Roberto Martin-Martin, De-An Huang, Yuke Zhu, Silvio Savarese, Li Fei-Fei
NeurIPS, 2019

[code] [poster]

A flexible neural network architecture for learning to plan from video demonstrations.

Continuous Relaxation of Symbolic Planner for One-Shot Imitation Learning
De-An Huang, Danfei Xu, Yuke Zhu, Silvio Savarese, Li Fei-Fei, Juan Carlos Niebles
IROS, 2019

[blog post]

One-shot imitation learning via hybrid neural-symbolic planning.

Situational Fusion of Visual Representation for Visual Navigation
William B. Shen, Danfei Xu, Yuke Zhu, Leonidas Guibas, Li Fei-Fei, Silvio Savarese
ICCV, 2019

Learning generalizable navigation policy from mid-level visual representations.

DenseFusion: 6D Object Pose Estimation by Iterative Dense Fusion
Chen Wang, Danfei Xu, Yuke Zhu, Roberto Martin-Martin, Cewu Lu, Li Fei-Fei, Silvio Savarese
CVPR, 2019

[website] [video] [code]

Dense RGB-depth sensor fusion for 6D object pose estimation.

Neural Task Graphs: Generalizing to Unseen Tasks from a Single Video Demonstration
De-An Huang*, Suraj Nair*, Danfei Xu*, Yuke Zhu, Animesh Garg, Li Fei-Fei, Silvio Savarese, Juan Carlos Niebles
CVPR, 2019 (Oral)

[blog post]

Generate executable task graphs from video demonstrations.

Neural Task Programming: Learning to Generalize Across Hierarchical Tasks
Danfei Xu*, Suraj Nair*, Yuke Zhu, Julian Gao, Animesh Garg, Li Fei-Fei, Silvio Savarese
ICRA, 2018

[website] [video] [Two Minute Papers] [blog post]

Neural Task Programming (NTP) is a meta-learning framework that learns to generate robot-executable neural programs from task demonstration video.

PointFusion: Deep Sensor Fusion for 3D Bounding Box Estimation
Danfei Xu, Ashesh Jain, Dragomir Anguelov
CVPR, 2018

End-to-end 3D Bounding Box Estimation via sensor fusion.

Scene Graph Generation by Iterative Message Passing
Danfei Xu, Yuke Zhu, Christopher B. Choy, Li Fei-Fei
CVPR, 2017

[website] [code]

We propose an end-to-end model that jointly infers object category, location, and relationships. The model learns to iteratively improve its prediction by passing messages on a scene graph.

3D-R2N2: A Unified Approach for Single and Multi-view 3D Object Reconstruction
Christopher B. Choy, Danfei Xu*, JunYoung Gwak*, Silvio Savarese
ECCV, 2016

[website] [code]

We propose an end-to-end 3D reconstruction model that unifies single- and multi-view reconstruction.

Model-Driven Feed-Forward Prediction for Manipulation of Deformable Objects
Yinxiao Li , Yan Wang , Yonghao Yue , Danfei Xu, Michael Case , Shih-Fu Chang , Eitan Grinspun , Peter K. Allen
IEEE TASE, 2016

[website]

Deformable object manipulation with an application of personal assitive robot.

This is the journal paper of our "laundry robot" series:
ICRA 2015
IROS 2015
ICRA 2016

Topometric localization on a road network
Danfei Xu, Hernan Badino, Daniel Huber
IROS, 2015

Vision-based localization on a probabilistic road network.

Tactile identification of objects using Bayesian exploration
Danfei Xu, Gerald E. Loeb, Jeremy Fishel
ICRA, 2013

Object classification using multi-modal tactile sensing.

Other Services
  • Reviewer: CVPR, ICCV, ECCV, IROS, ICRA, RSS, CoRL, T-RO, AAAI, IJRR, TPAMI, RA-L, NeurIPS, ICLR, ICML

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