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Gregory D. Hager

44 accepted papers

2024

VIHE: Virtual In-Hand Eye Transformer for 3D Robotic Manipulation

IROS 2024poster

In this work, we introduce the Virtual In-Hand Eye Transformer (VIHE), a novel method designed to enhance 3D manipulation capabilities through action-aware view rendering. VIHE autoregressively refines actions in multiple stages by conditioning on rendered views posed from action predictions in the…

Cited by 3SourcecodeScholar
2022

Coarse-to-Fine Incremental Few-Shot Learning

ECCV 2022poster

"Different from fine-tuning models pre-trained on a large-scale dataset of preset classes, class-incremental learning (CIL) aims to recognize novel classes over time without forgetting pre-trained classes. However, a given model will be challenged by test images with finer-grained classes, e.g., a b…

2022

SAGE: SLAM with Appearance and Geometry Prior for Endoscopy

ICRA 2022poster

In endoscopy, many applications (e.g., surgical navigation) would benefit from a real-time method that can simultaneously track the endoscope and reconstruct the dense 3D geometry of the observed anatomy from a monocular endoscopic video. To this end, we develop a Simultaneous Localization and Mappi…

Cited by 44SourcecodeScholar
2021

"Good Robot! Now Watch This!": Repurposing Reinforcement Learning for Task-to-Task Transfer

CoRL 2021poster

Modern Reinforcement Learning (RL) algorithms are not sample efficient to train on multi-step tasks in complex domains, impeding their wider deployment in the real world. We address this problem by leveraging the insight that RL models trained to complete one set of tasks can be repurposed to comple…

Cited by 13SourceScholar
2021

DASZL: Dynamic Action Signatures for Zero-shot Learning

AAAI 2021technical

There are many realistic applications of activity recognition where the set of potential activity descriptions is combinatorially large. This makes end-to-end supervised training of a recognition system impractical as no training set is practically able to encompass the entire label set. In this pap…

Cited by 32SourcePDFScholar
2021

Fine-Grained Activity Recognition for Assembly Videos

RA-L 2021

In this letter we address the task of recognizing assembly actions as a structure (e.g. a piece of furniture or a toy block tower) is built up from a set of primitive objects. Recognizing the full range of assembly actions requires perception at a level of spatial detail that has not been attempted

Cited by 19SourceScholar
2021

Guiding Multi-Step Rearrangement Tasks with Natural Language Instructions

CoRL 2021poster

Enabling human operators to interact with robotic agents using natural language would allow non-experts to intuitively instruct these agents. Towards this goal, we propose a novel Transformer-based model which enables a user to guide a robot arm through a 3D multi-step manipulation task with natural…

Cited by 31SourcecodeScholar
2021

Localization and Control of Magnetic Suture Needles in Cluttered Surgical Site with Blood and Tissue

IROS 2021poster

Real-time visual localization of needles is necessary for various surgical applications, including surgical automation and visual feedback. In this study we investigate localization and autonomous robotic control of needles in the context of our magneto-suturing system. Our system holds the potentia…

Cited by 8SourceScholar
2021

Neighborhood Normalization for Robust Geometric Feature Learning

CVPR 2021poster

Extracting geometric features from 3D models is a common first step in applications such as 3D registration, tracking, and scene flow estimation. Many hand-crafted and learning-based methods aim to produce consistent and distinguishable geometric features for 3D models with partial overlap. These me…

Cited by 6PDFcodeScholar
2021

Robust Policy Search for an Agile Ground Vehicle Under Perception Uncertainty

IROS 2021poster

Learning robust policies for robotic systems operating in presence of uncertainty is a challenging task. For safe navigation, in addition to the natural stochasticity of the environment and vehicle dynamics, the perception uncertainty associated with dynamic entities, e.g. pedestrians, must be accou…

Cited by 0SourceScholar
2020

"Good Robot!": Efficient Reinforcement Learning for Multi-Step Visual Tasks with Sim to Real Transfer

RA-L 2020

Current Reinforcement Learning (RL) algorithms struggle with long-horizon tasks where time can be wasted exploring dead ends and task progress may be easily reversed. We develop the SPOT framework, which explores within action safety zones, learns about unsafe regions without exploring them, and pri

Cited by 73SourcecodeScholar
2020

Anatomy-Aware Siamese Network: Exploiting Semantic Asymmetry for Accurate Pelvic Fracture Detection in X-ray Images

ECCV 2020poster

Trauma PXR are essential for instantaneous pelvic bone fracture detection. However, small, pathologically critical fractures can be missed, even by experienced clinicians, under the very limited diagnosis times allowed in urgent care. As a result, fracture CAD has very high demands to save time and…

Cited by 43SourcePDFScholar
2020

Autonomously Navigating a Surgical Tool Inside the Eye by Learning from Demonstration

ICRA 2020poster

A fundamental challenge in retinal surgery is safely navigating a surgical tool to a desired goal position on the retinal surface while avoiding damage to surrounding tissues, a procedure that typically requires tens-of-microns accuracy. In practice, the surgeon relies on depth-estimation skills to…

Cited by 35SourceScholar
2020

Extremely Dense Point Correspondences Using a Learned Feature Descriptor

CVPR 2020poster

High-quality 3D reconstructions from endoscopy video play an important role in many clinical applications, including surgical navigation where they enable direct video-CT registration. While many methods exist for general multi-view 3D reconstruction, these methods often fail to deliver satisfactory…

Cited by 62PDFcodeScholar
2020

Learning Geocentric Object Pose in Oblique Monocular Images

CVPR 2020poster

An object's geocentric pose, defined as the height above ground and orientation with respect to gravity, is a powerful representation of real-world structure for object detection, segmentation, and localization tasks using RGBD images. For close-range vision tasks, height and orientation have been d…

Cited by 29PDFcodeScholar
2020

Semantic Image Manipulation Using Scene Graphs

CVPR 2020poster

Image manipulation can be considered a special case of image generation where the image to be produced is a modification of an existing image. Image generation and manipulation have been, for the most part, tasks that operate on raw pixels. However, the remarkable progress in learning rich image and…

Cited by 146PDFcodeScholar
2019

The CoSTAR Block Stacking Dataset: Learning with Workspace Constraints

IROS 2019poster

A robot can now grasp an object more effectively than ever before, but once it has the object what happens next? We show that a mild relaxation of the task and workspace constraints implicit in existing object grasping datasets can cause neural network based grasping algorithms to fail on even a sim…

Cited by 12SourceScholar
2019

Uncertainty-Aware Occupancy Map Prediction Using Generative Networks for Robot Navigation

ICRA 2019poster

Efficient exploration through unknown environments remains a challenging problem for robotic systems. In these situations, the robot's ability to reason about its future motion is often severely limited by sensor field of view (FOV). By contrast, biological systems routinely make decisions by taking…

Cited by 67SourceScholar
2018

A Unified Framework for Multi-View Multi-Class Object Pose Estimation

ECCV 2018poster

One core challenge in object pose estimation is to ensure accurate and robust performance for large numbers of diverse foreground objects amidst complex background clutter. In this work, we present a scalable framework for accurately inferring six Degree-of-Freedom (6-DoF) pose for a large number of…

2018

Analyzing and Exploiting NARX Recurrent Neural Networks for Long-Term Dependencies

ICLR 2018workshop

Recurrent neural networks (RNNs) have achieved state-of-the-art performance on many diverse tasks, from machine translation to surgical activity recognition, yet training RNNs to capture long-term dependencies remains difficult. To date, the vast majority of successful RNN architectures alleviate th…

Cited by 36SourceScholar
2018

Evaluating Methods for End-User Creation of Robot Task Plans

IROS 2018poster

How can we enable users to create effective, perception-driven task plans for collaborative robots? We conducted a 35-person user study with the Behavior Tree-based CoSTAR system to determine which strategies for end user creation of generalizable robot task plans are most usable and effctive. CoSTA…

Cited by 47SourceScholar
2018

Guide Me: Interacting With Deep Networks

CVPR 2018poster

Interaction and collaboration between humans and intelligent machines has become increasingly important as machine learning methods move into real-world applications that involve end users. While much prior work lies at the intersection of natural language and vision, such as image captioning or ima…

Cited by 39SourcePDFScholar
2017

CoSTAR: Instructing collaborative robots with behavior trees and vision

ICRA 2017poster

For collaborative robots to become useful, end users who are not robotics experts must be able to instruct them to perform a variety of tasks. With this goal in mind, we developed a system for end-user creation of robust task plans with a broad range of capabilities. CoSTAR: the Collaborative System…

Cited by 226SourcecodeScholar
2017

Combining neural networks and tree search for task and motion planning in challenging environments

IROS 2017poster

Task and motion planning subject to Linear Temporal Logic (LTL) specifications in complex, dynamic environments requires efficient exploration of many possible future worlds. Model-free reinforcement learning has proven successful in a number of challenging tasks, but shows poor performance on tasks…

Cited by 153SourceScholar
2017

Deep Supervision With Shape Concepts for Occlusion-Aware 3D Object Parsing

CVPR 2017poster

Monocular 3D object parsing is highly desirable in various scenarios including occlusion reasoning and holistic scene interpretation. We present a deep convolutional neural network (CNN) architecture to localize semantic parts in 2D image and 3D space while inferring their visibility states, given a…

Cited by 110PDFScholar
2017

Learning in an Uncertain World: Representing Ambiguity Through Multiple Hypotheses

ICCV 2017poster

Many prediction tasks contain uncertainty. In some cases, uncertainty is inherent in the task itself. In future prediction, for example, many distinct outcomes are equally valid. In other cases, uncertainty arises from the way data is labeled. For example, in object detection, many objects of intere…

Cited by 235PDFScholar
2017

Temporal Convolutional Networks for Action Segmentation and Detection

CVPR 2017poster

The ability to identify and temporally segment fine-grained human actions throughout a video is crucial for robotics, surveillance, education, and beyond. Typical approaches decouple this problem by first extracting local spatiotemporal features from video frames and then feeding them into a tempora…

Cited by 2196PDFScholar
2016

Do what i want, not what i did: Imitation of skills by planning sequences of actions

IROS 2016poster

We propose a learning-from-demonstration approach for grounding actions from expert data and an algorithm for using these actions to perform a task in new environments. Our approach is based on an application of sampling-based motion planning to search through the tree of discrete, high-level action…

Cited by 28SourceScholar
2016

Hierarchical semantic parsing for object pose estimation in densely cluttered scenes

ICRA 2016

Densely cluttered scenes are composed of multiple objects which are in close contact and heavily occlude each other. Few existing 3D object recognition systems are capable of accurately predicting object poses in such scenarios. This is mainly due to the presence of objects with textureless surfaces

Cited by 19SourceScholar
2016

Incremental scene understanding on dense SLAM

IROS 2016poster

We present an architecture for online, incremental scene modeling which combines a SLAM-based scene understanding framework with semantic segmentation and object pose estimation. The core of this approach comprises a probabilistic inference scheme that predicts semantic labels for object hypotheses…

Cited by 36SourceScholar
2016

Sensor substitution for video-based action recognition

IROS 2016poster

There are many applications where domain-specific sensing, such as accelerometers, kinematics, or force sensing, provide unique and important information for control or for analysis of motion. However, it is not always the case that these sensors can be deployed or accessed beyond laboratory environ…

Cited by 34SourceScholar
2016

Unsupervised surgical data alignment with application to automatic activity annotation

ICRA 2016

Robotic surgery and other minimally-invasive surgical techniques are an integral part of patient care, and readily yield large amounts of data. Surgical tool motion (kinematic data) contains information that is useful for assessment and education. Typically, assessment and education tools that rely

Cited by 16SourceScholar
2015

A framework for end-user instruction of a robot assistant for manufacturing

ICRA 2015poster

Small Manufacturing Entities (SMEs) have not incorporated robotic automation as readily as large companies due to rapidly changing product lines, complex and dexterous tasks, and the high cost of start-up. While recent low-cost robots such as the Universal Robots UR5 and Rethink Robotics Baxter are…

Cited by 144SourceScholar
2015

An incremental approach to learning generalizable robot tasks from human demonstration

ICRA 2015poster

Dynamic Movement Primitives (DMPs) are a common method for learning a control policy for a task from demonstration. This control policy consists of differential equations that can create a smooth trajectory to a new goal point. However, DMPs only have a limited ability to generalize the demonstratio…

Cited by 56SourceScholar
2015

Beyond Spatial Pooling: Fine-Grained Representation Learning in Multiple Domains

CVPR 2015poster

Object recognition systems have shown great progress over recent years. However, creating object representations that are robust to changes in viewpoint while capturing local visual details continues to be a challenge. In particular, recent convolutional architectures employ spatial pooling to achie…

Cited by 39SourcePDFScholar
2015

Hierarchical Sparse and Collaborative Low-Rank representation for emotion recognition

ICASSP 2015accepted

In this paper, we design a Collaborative-Hierarchical Sparse and Low-Rank (C-HiSLR) model that is natural for recognizing human emotion in visual data. Previous attempts require explicit expression components, which are often unavailable and difficult to recover. Instead, our model exploits the low-…

Cited by 0SourceScholar