Affordances from Human Videos as a Versatile Representation for Robotics

Shikhar Bahl*1,2    Russell Mendonca*1    Lili Chen2    Unnat Jain1,2    Deepak Pathak1
1Carnegie Mellon University          2Meta AI CVPR 2023
Paper arXiv Video Code (Coming Soon) Dataset (Coming Soon) Summary

Given a scene, our approach (VRB) learns actionable representations for robot learning. VRB predicts contact points and a post-contact trajectory learned from human videos .

Abstract

Building a robot that can understand and learn to interact by watching humans has inspired several vision problems. However, despite some successful results on static datasets, it remains unclear how current models can be used on a robot directly. In this paper, we aim to bridge this gap by leveraging videos of human interactions in an environment centric manner. Utilizing internet videos of human behavior, we train a visual affordance model that estimates where and how in the scene a human is likely to interact. The structure of these behavioral affordances directly enables the robot to perform many complex tasks. We show how to seamlessly integrate our affordance model with four robot learning paradigms including offline imitation learning, exploration, goal-conditioned learning, and action parameterization for reinforcement learning. We show the efficacy of our approach, which we call Vision-Robotics Bridge (VRB) as we aim to seamlessly integrate computer vision techniques with robotic manipulation, across 4 real world environments, over 10 different tasks, and 2 robotic platforms operating in the wild.

Extracting Affordances Without Extra Annotations

Robot-centric Affordances: While visual affordances have been studied extensively in computer vision, applying them to robotics needs smart tweaks. As we learn from large-scale human videos but apply to robots, we seek an agent-agnostic affordance to facilitate this transfer. Therefore, we define affordance as:

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Extracting Visual Affordances from Human Videos

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We extract affordances from large scale human video datasets such as Ego4D and Epic Kitchens. We use off the shelf hand-object interaction detectors to find the contact region and post contact wrist trajectory.


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Illustration of annotation pipeline (Left) Find the frame with hand-object contact. (Middle) Track the wrist to obtain the post contact trajectory. (Right) Map both to the first human entry frame for reference.

We first find the contact point using a hand object interaction detector. We find the post contact trajectory by tracking the wrist after the contact frame. Once we have detected these frames, a major issue is that the the human is still in the scene , leading to a distribution shift.



Our solution is to simply map the affordances back to the first frame without the human.

We use available camera information to project both the contact points and the post-contact trajectory to the human-agnostic frame. This frame is used as input to our model.


Our Affordance Pipeline

Full Pipeline

VRB: Model

VRB Model

Our model takes a human-agnostic frame as input. The contact head outputs a contact heatmap (left) and the trajectory transformer predicts wrist waypoints (orange). This output can be directly used at inference time (with sparse 3D information, such as depth, and robot kinematics).

Applications to Robotics

We benchmark VRB on 10+ Tasks, 2 robot morphologies, 4 learning paradigms

Visualizing Affordance Model Output



Robot Learning Paradigms

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Robot Learning Paradigms (Top-Left) Affordance-model driven data collection for offline imitation. (Top-Right) Reward free exploration. (Bottom-Left) Goal-conditioned policy learning with our affordance model. (Bottom-Right) Using the affordance model outputs to reparameterize actions.

Affordance Model-based Data Collection

Data Collection Results

Goal-Conditioned Learning

GCL Results

Reward-Free Exploration

Exploration Results

Visual Affordances as Action Spaces

Affordance Action Space
Action Space Results

Project Video

Simulation Benchmark

Kitchen Simulation

We have also tested VRB on a simulation benchmark, specifically, the Franka Kitchen benchmark from D4RL. Our method demonstrates superior performance compared to the baselines on three distinct tasks within the benchmark.

Simulation Results

Handling Rare Objects

Rare Objects

VRB demonstrates effective handling of rare objects, outperforming the Hotspots baseline in grasping various held-out items. This showcases VRB's adaptability to different tasks and environments.

BibTeX

@inproceedings{bahl2023affordances,
              title={Affordances from Human Videos as a Versatile Representation for Robotics},
              author={Bahl, Shikhar and Mendonca, Russell and Chen, Lili and Jain, Unnat and Pathak, Deepak},
              journal={CVPR},
              year={2023}
            }

Acknowledgements

We thank Shivam Duggal, Yufei Ye and Homanga Bharadhwaj for fruitful discussions and are grateful to Shagun Uppal, Ananye Agarwal, Murtaza Dalal and Jason Zhang for comments on early drafts of this paper. RM, LC, and DP are supported by NSF IIS-2024594, ONR MURI N00014-22-1-2773 and ONR N00014-22-1-2096.