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Sehoon Ha

59 accepted papers

2026

Dynamic Policy Learning for Legged Robot With Simplified Model Pretraining and Model-Homotopy-Inspired Transfer

RA-L 2026

Generating dynamic motions for legged robots remains a challenging problem. While reinforcement learning has achieved notable success in various legged locomotion tasks, producing highly dynamic behaviors often requires extensive reward tuning or high-quality demonstrations. Leveraging reduced-order

Cited by 0SourceScholar
2026

EMMA: Scaling Mobile Manipulation Via Egocentric Human Data

ICRA 2026poster

Scaling mobile manipulation imitation learning is bottlenecked by expensive mobile robot teleoperation. We present Egocentric Mobile MAnipulation (EMMA), an end-to-end framework training mobile manipulation policies from human mobile manipulation data with static robot data, sidestepping mobile tele…

2026

EMMA: Scaling Mobile Manipulation via Egocentric Human Data

RA-L 2026

Scaling mobile manipulation imitation learning is bottlenecked by expensive mobile robot teleoperation. We present Egocentric Mobile MAnipulation (EMMA), an end-to-end framework training mobile manipulation policies from human mobile manipulation data with static robot data, sidestepping mobile tele

Cited by 31SourcecodeScholar
2026

Flip Stunts on Bicycle Robots Using Iterative Motion Imitation

ICRA 2026poster

This work demonstrates a front-flip on bicycle robots via reinforcement learning, particularly by imitating reference motions that are infeasible and imperfect. To address this, we propose Iterative Motion Imitation (IMI), a method that iteratively imitates trajectories generated by prior policy rol…

2026

Opt2Skill: Imitating Dynamically-Feasible Whole-Body Trajectories for Versatile Humanoid Loco-Manipulation

ICRA 2026poster

Humanoid robots are designed to perform diverse loco-manipulation tasks. However, they face challenges due to their high-dimensional and unstable dynamics, as well as the complex contact-rich nature of the tasks. Model-based optimal control methods offer flexibility to define precise motion but are …

2026

PPF: Pre-Training and Preservative Fine-Tuning of Humanoid Locomotion Via Model-Assumption-Based Regularization

ICRA 2026poster

Humanoid locomotion is a challenging task due to its inherent complexity and high-dimensional dynamics, as well as the need to adapt to diverse and unpredictable environments. In this work, we introduce a novel learning framework for effectively training a humanoid locomotion policy that imitates th…

2025

Do Looks Matter? Exploring Functional and Aesthetic Design Preferences for a Robotic Guide Dog

ICRA 2025

Dog guides offer an effective mobility solution for blind or visually impaired (BVI) individuals, but conventional dog guides have limitations including the need for care, potential distractions, societal prejudice, high costs, and limited availability. To address these challenges, we seek to develo

Cited by 0SourceScholar
2025

Learning a High-Quality Robotic Wiping Policy Using Systematic Reward Analysis and Visual-Language Model Based Curriculum

ICRA 2025

Autonomous robotic wiping is an important task in various industries, ranging from industrial manufacturing to sanitization in healthcare. Deep reinforcement learning (Deep RL) has emerged as a promising algorithm, however, it often suffers from a high demand for repetitive reward engineering. Inste

Cited by 1SourceScholar
2025

Opt2Skill: Imitating Dynamically-Feasible Whole-Body Trajectories for Versatile Humanoid Loco-Manipulation

RA-L 2025

Humanoid robots are designed to perform diverse loco-manipulation tasks. However, they face challenges due to their high-dimensional and unstable dynamics, as well as the complex contact-rich nature of the tasks. Model-based optimal control methods offer flexibility to define precise motion but are

Cited by 50SourcecodeScholar
2025

PPF: Pre-Training and Preservative Fine-Tuning of Humanoid Locomotion via Model-Assumption-Based Regularization

RA-L 2025

Humanoid locomotion is a challenging task due to its inherent complexity and high-dimensional dynamics, as well as the need to adapt to diverse and unpredictable environments. In this work, we introduce a novel learning framework for effectively training a humanoid locomotion policy that imitates th

Cited by 5SourceScholar
2025

Privileged-Dreamer: Explicit Imagination of Privileged Information for Rapid Adaptation of Learned Policies

ICRA 2025

Numerous real-world control problems involve dynamics and objectives affected by unobservable hidden parameters, ranging from autonomous driving to robotic manipulation, which cause performance degradation during sim-to-real transfer. To represent these kinds of domains, we adopt hiddenparameter Mar

Cited by 2SourceScholar
2025

Tactile sensing enables vertical obstacle negotiation for elongate many-legged robots

RSS 2025poster

Many-legged elongated robots show promise for reliable mobility on rugged landscapes. However, most studies on these systems focus on motion planning in the 2D horizontal plane (e.g., translation and rotation) without addressing rapid vertical motion. Despite their success on mild rugged terrains, r…

Cited by 0PDFScholar
2025

Unsupervised Skill Discovery as Exploration for Learning Agile Locomotion

CoRL 2025poster

Exploration is crucial for legged robots to learn agile locomotion behaviors capable of overcoming diverse obstacles. For example, a robot may need to try different contact patterns and momentum profiles to successfully jump over an obstacle—but encouraging such diverse exploration is inherently ch…

Cited by 0SourceScholar
2024

AAMDM: Accelerated Auto-regressive Motion Diffusion Model

CVPR 2024poster

Interactive motion synthesis is essential in creating immersive experiences in entertainment applications such as video games and virtual reality. However generating animations that are both high-quality and contextually responsive remains a challenge. Traditional techniques in the game industry can…

Cited by 5SourcePDFScholar
2024

ASC: Adaptive Skill Coordination for Robotic Mobile Manipulation

RA-L 2024

We present Adaptive Skill Coordination (ASC) – an approach for accomplishing long-horizon tasks like mobile pick-and-place (i.e., navigating to an object, picking it, navigating to another location, and placing it). ASC consists of three components – (1) a library of basic visuomotor <italic xmlns:m

Cited by 74SourceScholar
2024

BayRnTune: Adaptive Bayesian Domain Randomization via Strategic Fine-tuning

IROS 2024poster

Domain randomization (DR), which entails training a policy with randomized dynamics, has proven to be a simple yet effective algorithm for reducing the gap between simulation and the real world. However, DR often requires careful tuning of randomization parameters. Methods like Bayesian Domain Rando…

Cited by 3SourceScholar
2024

CrossLoco: Human Motion Driven Control of Legged Robots via Guided Unsupervised Reinforcement Learning

ICLR 2024poster

Human motion driven control (HMDC) is an effective approach for generating natural and compelling robot motions while preserving high-level semantics. However, establishing the correspondence between humans and robots with different body structures is not straightforward due to the mismatches in kin…

Cited by 9SourcePDFScholar
2024

HM3D-OVON: A Dataset and Benchmark for Open-Vocabulary Object Goal Navigation

IROS 2024poster

We present the Habitat-Matterport 3D Open Vocabulary Object Goal Navigation dataset (HM3D-OVON), a large-scale benchmark that broadens the scope and semantic range of prior Object Goal Navigation (ObjectNav) benchmarks. Leveraging the HM3DSem dataset, HM3D-OVON incorporates over 15k annotated instan…

Cited by 10SourceScholar
2024

Learning manipulation of steep granular slopes for fast Mini Rover turning

ICRA 2024poster

Future planetary exploration missions will require reaching challenging regions such as craters and steep slopes. Such regions are ubiquitous and present science-rich targets potentially containing information regarding the planet’s internal structure. Steep slopes consisting of low-cohesion regolit…

Cited by 2SourceScholar
2024

VLFM: Vision-Language Frontier Maps for Zero-Shot Semantic Navigation

ICRA 2024poster

Understanding how humans leverage semantic knowledge to navigate unfamiliar environments and decide where to explore next is pivotal for developing robots capable of human-like search behaviors. We introduce a zero-shot navigation approach, Vision-Language Frontier Maps (VLFM), which is inspired by…

Cited by 97SourcecodeScholar
2023

ARMP: Autoregressive Motion Planning for Quadruped Locomotion and Navigation in Complex Indoor Environments

IROS 2023poster

Generating natural and physically feasible motions for legged robots has been a challenging problem due to its complex dynamics. In this work, we introduce a novel learning-based framework of autoregressive motion planner (ARMP) for quadruped locomotion and navigation. Our method can generate motion…

Cited by 2SourceScholar
2023

Imitating and Finetuning Model Predictive Control for Robust and Symmetric Quadrupedal Locomotion

RA-L 2023

Control of legged robots is a challenging problem that has been investigated by different approaches, such as model-based control and learning algorithms. This work proposes a novel Imitating and Finetuning Model Predictive Control (IFM) framework to take the strengths of both approaches. Our framew

Cited by 28SourceScholar
2023

Learning a Single Policy for Diverse Behaviors on a Quadrupedal Robot Using Scalable Motion Imitation

IROS 2023poster

Learning various motor skills for quadrupedal robots is a challenging problem that requires careful design of task-specific mathematical models or reward descriptions. In this work, we propose to learn a single capable policy using deep reinforcement learning by imitating a large number of reference…

Cited by 4SourceScholar
2023

Learning and Adapting Agile Locomotion Skills by Transferring Experience

RSS 2023poster

Legged robots have enormous potential in their range of capabilities, from navigating unstructured terrains to high-speed running. However, these capabilities bring with them difficult control problems, and designing controllers for highly agile dynamic motions remains a substantial challenge for ro…

2023

On Designing a Learning Robot: Improving Morphology for Enhanced Task Performance and Learning

IROS 2023poster

As robots become more prevalent, optimizing their design for better performance and efficiency is becoming increasingly important. However, current robot design practices overlook the impact of perception and design choices on a robot's learning capabilities. To address this gap, we propose a compre…

Cited by 1SourcecodeScholar
2023

Transforming a Quadruped into a Guide Robot for the Visually Impaired: Formalizing Wayfinding, Interaction Modeling, and Safety Mechanism

CoRL 2023poster

This paper explores the principles for transforming a quadrupedal robot into a guide robot for individuals with visual impairments. A guide robot has great potential to resolve the limited availability of guide animals that are accessible to only two to three percent of the potential blind or visual…

Cited by 13SourceScholar
2023

ViNL: Visual Navigation and Locomotion Over Obstacles

ICRA 2023poster

We present Visual Navigation and Locomotion over obstacles (ViNL), which enables a quadrupedal robot to navigate unseen apartments while stepping over small obstacles that lie in its path (e.g., shoes, toys, cables), similar to how humans and pets lift their feet over objects as they walk. ViNL cons…

Cited by 29SourcecodeScholar
2022

Benchmarking Augmentation Methods for Learning Robust Navigation Agents: the Winning Entry of the 2021 iGibson Challenge

IROS 2022poster

Recent advances in deep reinforcement learning and scalable photorealistic simulation have led to increasingly mature embodied AI for various visual tasks, including navigation. However, while impressive progress has been made for teaching embodied agents to navigate static environments, much less p…

Cited by 11SourceScholar
2022

Graph-based Cluttered Scene Generation and Interactive Exploration using Deep Reinforcement Learning

ICRA 2022poster

We introduce a novel method to teach a robotic agent to interactively explore cluttered yet structured scenes, such as kitchen pantries and grocery shelves, by leveraging the physical plausibility of the scene. We propose a novel learning framework to train an effective scene exploration policy to d…

Cited by 17SourceScholar
2022

Human Motion Control of Quadrupedal Robots using Deep Reinforcement Learning

RSS 2022poster

A motion-based control interface promises flexible robot operations in dangerous environments by combining user intuitions with the robot's motor capabilities. However, designing a motion interface for non-humanoid robots, such as quadrupeds or hexapods, is not straightforward because different dyna…

Cited by 31SourcePDFScholar
2022

Improving Safety in Deep Reinforcement Learning using Unsupervised Action Planning

ICRA 2022poster

One of the key challenges to deep reinforcement learning (deep RL) is to ensure safety at both training and testing phases. In this work, we propose a novel technique of unsupervised action planning to improve the safety of on-policy reinforcement learning algorithms, such as trust region policy opt…

Cited by 19SourceScholar
2022

Legged Robots that Keep on Learning: Fine-Tuning Locomotion Policies in the Real World

ICRA 2022poster

Legged robots are physically capable of traversing a wide range of challenging environments, but designing controllers that are sufficiently robust to handle this diversity has been a long-standing challenge in robotics. Reinforcement learning presents an appealing approach for automating the contro…

Cited by 136SourceScholar
2022

Safe Reinforcement Learning for Legged Locomotion

IROS 2022poster

Designing control policies for legged locomotion11In this work, we specifically consider quadruped locomotion. is complex due to the under-actuated and non-continuous robot dynamics. Model-free reinforcement learning provides promising tools to tackle this challenge. However, a major bottleneck of a…

Cited by 42SourceScholar
2021

A Few Shot Adaptation of Visual Navigation Skills to New Observations using Meta-Learning

ICRA 2021poster

Target-driven visual navigation is a challenging problem that requires a robot to find the goal using only visual inputs. Many researchers have demonstrated promising results using deep reinforcement learning (deep RL) on various robotic platforms, but typical end-to-end learning is known for its po…

Cited by 18SourceScholar
2021

Error-Aware Policy Learning: Zero-Shot Generalization in Partially Observable Dynamic Environments

RSS 2021poster

Simulation provides a safe and efficient way to generate useful data for learning complex robotic tasks. However; matching simulation and real-world dynamics can be quite challenging; especially for systems that have a large number of unobserved or unmeasurable parameters; which may lie in the robot…

Cited by 4SourcePDFScholar
2021

PODS: Policy Optimization via Differentiable Simulation

ICML 2021spotlight

Current reinforcement learning (RL) methods use simulation models as simple black-box oracles. In this paper, with the goal of improving the performance exhibited by RL algorithms, we explore a systematic way of leveraging the additional information provided by an emerging class of differentiable si…

Cited by 59SourcePDFScholar
2021

Success Weighted by Completion Time: A Dynamics-Aware Evaluation Criteria for Embodied Navigation

IROS 2021poster

We present Success weighted by Completion Time (SCT), a new metric for evaluating navigation performance for mobile robots. Several related works on navigation have used Success weighted by Path Length (SPL) as the primary method of evaluating the path an agent makes to a goal location, but SPL is l…

Cited by 27SourceScholar
2021

Visual-Locomotion: Learning to Walk on Complex Terrains with Vision

CoRL 2021poster

Vision is one of the most important perception modalities for legged robots to safely and efficiently navigate uneven terrains, such as stairs and stepping stones. However, training robots to effectively understand high-dimensional visual input for locomotion is a challenging problem. In this work,…

Cited by 86SourceScholar
2020

Learning a Control Policy for Fall Prevention on an Assistive Walking Device

ICRA 2020poster

Fall prevention is one of the most important components in senior care. We present a technique to augment an assistive walking device with the ability to prevent falls. Given an existing walking device, our method develops a fall predictor and a recovery policy by utilizing the onboard sensors and a…

Cited by 29SourceScholar
2020

Zero-shot Imitation Learning from Demonstrations for Legged Robot Visual Navigation

ICRA 2020poster

Imitation learning is a popular approach for training effective visual navigation policies. However, collecting expert demonstrations for legged robots is challenging as these robots can be hard to control, move slowly, and cannot operate continuously for long periods of time. In this work, we propo…

Cited by 32SourceScholar
2019

Learning to Walk Via Deep Reinforcement Learning

RSS 2019poster

Deep reinforcement learning (deep RL) holds the promise of automating the acquisition of complex controllers that can map sensory inputs directly to low-level actions. In the domain of robotic locomotion, deep RL could enable learning locomotion skills with minimal engineering and without an explici…

Cited by 613SourcePDFScholar
2018

Improving Model-Based Balance Controllers Using Reinforcement Learning and Adaptive Sampling

ICRA 2018poster

Balance control to recover from a wide range of disturbances is an important skill for humanoid robots. Traditionally, researchers have often designed a balance controller by applying optimal control theory on a simplified model that abstracts the full-body dynamics. However, the resulting controlle…

Cited by 6SourceScholar
2017

Joint Optimization of Robot Design and Motion Parameters using the Implicit Function Theorem

RSS 2017poster

We present a novel computational approach to optimizing the morphological design of robotic devices. Our framework takes as input a parameterized robot design, and a motion plan consisting of end-effector trajectories and/or a body trajectory. The algorithm we propose is used to optimize a set of de…

Cited by 98SourcePDFScholar