Nahyun Lee

Mrs. Nahyun Lee

Smart Mobility R&D Division, KOREA INSTITUTE OF ROBOTICS & TECHNOLOGY CONVERGENCE, Pohang, Gyeongbuk, Republic of Korea
orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 August 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
JKJi-Wook Kwon
Ji-Wook Kwon
HLHyoujun Lee
Hyoujun Lee
JLJongdeuk Lee
Jongdeuk Lee
NLNahyun Lee
Nahyun Lee
JKJong Chan Kim
Jong Chan Kim
YCYong-Ho Choi
Yong-Ho Choi
This paper introduces a UWB-based human-following system for polar-exploration robots, integrating obstacle and crevasse avoidance functions to enhance the safety and efficiency of explorers in extreme environments. The proposed system determines the relative position of the explorer using UWB anchors and tags. It also utilizes real-time local obstacle mapping and path-planning algorithms to find safe paths that avoid collisions with obstacles. Simulation and real-world experiments confirm that the proposed system operates effectively in polar environments, reducing the operational burden on explorers and increasing mission success rates.

5 October 2025 in Sensors
Verified
Journal Article
Open access
PDF file
JLJungwoo Lee
Jungwoo Lee
HKHyogon Kim
Hyogon Kim
JKJi-Wook Kwon
Ji-Wook Kwon
SYSung-Jo Yun
Sung-Jo Yun
NLNahyun Lee
Nahyun Lee
Jin-Ho SuhJin-Ho Suh
Jin-Ho Suh
Tableware objects such as plates, bowls, and cups are usually textureless, uniform in color, and vary widely in shape, making it difficult to apply conventional pose estimation methods that rely on texture cues or object-specific CAD models. These limitations present a significant obstacle to robotic manipulation in restaurant environments, where reliable six-degree-of-freedom (6-DoF) pose estimation is essential for autonomous grasping and collection. To address this problem, we propose a model-free and texture-free 6-DoF pose estimation framework based on a transformer encoder architecture. This method uses only geometry-based features extracted from depth images, including surface vertices and rim normals, which provide strong structural priors. The pipeline begins with object detection and segmentation using a pretrained video foundation model, followed by the generation of uniformly partitioned grids from depth data. For each grid cell, centroid positions, and surface normals are computed and processed by a transformer-based model that jointly predicts object rotation and translation. Experiments with ten types of tableware demonstrate that the method achieves an average rotational error of 3.53 degrees and a translational error of 13.56 mm. Real-world deployment on a mobile robot platform with a manipulator further validated its ability to autonomously recognize and collect tableware, highlighting the practicality of the proposed geometry-driven approach for service robotics.

23 May 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
JKJi-Wook Kwon
Ji-Wook Kwon
SYSung-Jo Yun
Sung-Jo Yun
HKHyogon Kim
Hyogon Kim
JLJungwoo Lee
Jungwoo Lee
NLNahyun Lee
Nahyun Lee
GCGoobong Chung
Goobong Chung
This paper proposes a coupled-error-based formation control algorithm for the rapid formation completion of multi-robot systems. We consider a multi-robot system with omni-directional robots with swerve-driving mechanisms and a communication system with minimized constraints. This paper introduces a coupled error that links the distance errors with the leading robot and the following robot through a coupling ratio. We propose a controller using the coupled error to achieve the control objectives of this paper. Unlike existing results that only use the information of the preceding robot, this algorithm couples the information of both the preceding robot and one’s follower. Using the proposed error-coupling-based formation control algorithm, multi-robot systems can quickly establish formations for collaboration, allowing tasks to commence swiftly and reducing deformations in formations due to speed variations. With stability analysis and simulation results for the practical application of the proposed algorithm, the approach has been verified to improve the speed of both the completion of the formation and overall system trajectory tracking, balancing trade-offs between them.