https://scholar.dgist.ac.kr/handle/20.500.11750/104 2026-04-05T02:21:11Z 2026-04-05T02:21:11Z Lee, Sanghoon Kim, Taehun Chae, Jiyeong Park, Kyung-Joon https://scholar.dgist.ac.kr/handle/20.500.11750/59967 2026-02-09T07:10:17Z 2025-09-22T15:00:00Z

Title: Poster: How to Send Large Data in ROS 2 Author(s): Lee, Sanghoon; Kim, Taehun; Chae, Jiyeong; Park, Kyung-Joon Abstract: High-resolution data streams-such as images, Li-DAR point-clouds-are common in robotic communication, yet Robot Operating System 2 (ROS 2) struggles to transmit these streams due to increased average latency. On lossy wireless links, the default DDS communication stack in ROS 2 suffers significant performance degradation. This paper presents the first comprehensive network-layer analysis of ROS 2's DDS stack operating over wireless links with large payloads. We analyze three network bottlenecks that emerge during large-payload data transfers and presents DDS-level optimizations for each one. The proposed solutions are exposed through an XML-based QoS configuration interface, allowing them to be easily tuned. Experiments demonstrate that our approach transmits large-payload data successfully while maintaining lower latency than existing methods.

2025-09-22T15:00:00Z Park, Hyung-Seok Lee, Sanghoon Um, Doo-Sik Ryu, Hyunho Park, Kyung-Joon https://scholar.dgist.ac.kr/handle/20.500.11750/59902 2026-02-04T11:10:12Z 2025-05-19T15:00:00Z

Title: An Analytical Latency Model of the Data Distribution Service in ROS 2 Author(s): Park, Hyung-Seok; Lee, Sanghoon; Um, Doo-Sik; Ryu, Hyunho; Park, Kyung-Joon Abstract: After its initial release in 2007, the robot operating system (ROS) has been widely adopted as an open-source robotics middleware suite. In 2017, ROS 2 is introduced to offer enhanced performance, and it has since become the de facto standard for robot software development. In this paper, we propose an analytical latency model for the data distribution service (DDS) in ROS 2. DDS operates at the application layer on top of the user datagram protocol (UDP). In ROS 2, retransmissions for reliable data delivery are handled at the application layer, resulting in latency characteristics different from those of the transmission control protocol (TCP). We derive a closed-form analytical model to characterize the latency of DDS reliable data delivery in ROS 2, taking into account key parameters such as the packet delivery ratio, the data period, and the heartbeat period in DDS. Our extensive empirical study shows that the proposed model matches well with the empirical data, with an average error of 6.88 % across 35 different scenarios.

2025-05-19T15:00:00Z Lee, Sanghoon Chae, Jiyeong Park, Kyung-Joon https://scholar.dgist.ac.kr/handle/20.500.11750/59148 2025-11-06T10:40:12Z 2025-07-07T15:00:00Z

Title: Integrating ROS 2 and Physical AI: Architecture and Challenges Author(s): Lee, Sanghoon; Chae, Jiyeong; Park, Kyung-Joon Abstract: Physical Artificial Intelligence (Physical AI) embeds sensors, actuators, and AI algorithms to enable robots to learn and adapt in real-world settings. ROS 2, with its DDS-based publisher-subscriber model and advanced Quality of Service (QoS) features, forms a robust platform for such real-time, distributed applications. Yet, integrating AI within a Cyber-Physical System (CPS) framework raises concerns about resource constraints, safety, and uncertainties. This paper explores how to incorporate Physical AI into ROS 2 by fully automating or partially augmenting robot functionalities, focusing on topic structures, message formats, and key QoS considerations. We highlight major challenges - data availability, data loss, inference latency, and security vulnerabilities - and emphasize the importance of a holistic approach to ensure reliability and safety.

2025-07-07T15:00:00Z 김태우 이동형 박경준 https://scholar.dgist.ac.kr/handle/20.500.11750/57531 2025-07-25T02:43:19Z 2024-01-31T15:00:00Z

Title: 차량 군집 주행 시스템의 String Stability에 미치는 통신 지연의 동역학적 영향 Author(s): 김태우; 이동형; 박경준 Abstract: 본 논문은 차량 군집 주행 중 통신 지연 시간이 군집의 안정성에 미치는 영향을 분석한다. 특히, 차량 간의 동적 반응이 통신 지연에 어떻게 영향을 받는지를 모델링하고, String Stability를 측정하여 지연 시간이 변동할 때 시스템의 안정성이 어떻게 변화하는 지를 확인한다. 이를 통해 통신 기술의 발전이 차량 군집 주행 시스템의 효율성과 안전성을 어떻게 향상시킬 수 있는 지에 대한 이해를 증진시키고자 한다.

2024-01-31T15:00:00Z