https://scholar.dgist.ac.kr/handle/20.500.11750/900 2026-04-04T08:11:52Z https://scholar.dgist.ac.kr/handle/20.500.11750/59996 Title: Analysis and Design of a Bistable Tail for a Hybrid Throwbot in a Step-Overcoming Scenario Author(s): Ju, Insung; Kim, Minseop; Keum, Jaeyeong; Lim, Seunghyun; Yun, Dongwon Abstract: In this study, we propose a reconfigurable laminate mechanism based bistable tail for Throwbot transforming into a ball type and a wheel type. Various robots such as snake robots, drones, and throwing robots for life-saving missions on behalf of humans at disaster sites have been studied. In particular the hybrid type throwing robot can have both the throwing ease of the ball type and the driving stability of the wheel type. However, it requires the tail to be stored inside when being thrown and to be rigidly deployed when driving. To satisfy these requirements, we developed a foldable tail based on scissor lift structure in our previous study. But, such a structure was composed of only rigid parts, which caused interference with other parts when stored, and difficulty about changing the maximum deployed tail length further. To overcome these limitations, we wanted to develop a bistable tail suitable for the hybrid type that can maintain a bendable state and a rigid state. Before actual development, we calculate the minimum tail length for overcoming obstacle through statics analysis. Then, we design a bistable structure utilizing a reconfigurable laminate mechanism. Next, we calculate the design constraints to mount it on the actual robot. Finally, the developed tail is mounted on the actual Throwbot to perform obstacle overcoming experiments. We confirm that it can secure both ease throwing and stable obstacle overcoming ability. Through this, we propose a bistable tail suitable for the hybrid type throwing robots. 2025-10-21T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59952 Title: Supercritical Sliding-Mode Control for Position Tracking of PMSM With Disturbance Rejection Author(s): Kim, Jisu; Choi, Sunghyun; Yun, Dongwon Abstract: In highly dynamic environments, such as industrial automation systems with frequent load changes or electric vehicles, ensuring both robustness and high-precision control remains challenging, particularly in the position control of permanent magnet synchronous motors. Sliding-mode control (SMC) is widely used for its robustness, but traditional SMC methods often suffer from chattering and slow convergence, limiting overall system performance. To address these limitations, this study proposes a robust SMC approach incorporating a novel nonlinear sliding surface inspired by the supercritical pitchfork bifurcation concept. Additionally, a new reaching law is introduced to attenuate chattering and ensure fast convergence of the sliding variable to zero within a finite time. The proposed method also integrates a proportional-integral observer (PIO) with the equivalent-input disturbance (EID) framework to enhance disturbance rejection under both matched and mismatched uncertainties. The stability of the proposed controller was verified using Lyapunov stability analysis, and its performance was validated through simulations and real-world experiments. Comparative evaluations demonstrated that the proposed reaching law significantly reduces chattering amplitude by over 50 % and improves convergence speed by approximately 5.6 times faster than conventional methods. Furthermore, the system's disturbance-rejection capability under matched and mismatched uncertainties is enhanced through the PIO+EID structure. These results confirmed the robust performance of the controller under unknown disturbances. This paper is accompanied by a video that demonstrates the proposed control strategy and provides a comparison with traditional controllers. © 2025 Elsevier B.V., All rights reserved. 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59950 Title: 형상 적응 파지를 위한 소형 부족 구동 기반 그리퍼 개발 Author(s): 금재영; 김동현; 정영준; 송진혁; 윤동원 Abstract: This paper proposes a wire-driven gripper that actuates three fingers using a single motor, aiming to enable stable object manipulation in confined and unstructured environments such as battlefields and disaster sites. Unmanned robots operating in such scenarios are increasingly required to perform missions including reconnaissance, search, rescue, and hazardous material removal. To fulfill these tasks, compact and reliable gripper systems are essential. Conventional grippers are categorized into soft grippers, which offer excellent shape adaptability through flexible materials, and rigid grippers, which provide structural strength. However, soft grippers are unsuitable for field environments due to limited stiffness, while rigid grippers lack adaptability for irregular objects. The proposed gripper enhances adaptability by leveraging wire-driven mechanism and reduces size and complexity through single-motor actuation. The design was validated through workspace analysis and motor torque estimation, and grasping experiments confirmed its performance. This paper demonstrates that the proposed gripper is well-suited for unmanned robots tasked with hazardous material handling and rescue operations in constrained environments. 2025-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59257 Title: 부상 플랫폼 Author(s): 이진이; 김명진; 송봉섭; 윤동원; 임기홍; 박종원 Abstract: 본 발명은 부상 플랫폼에 관한 것으로 더욱 상세하게는 쓰러스터 밸브 개폐와 노즐 면적 제어를 통한 추력원의 배출량 제어 및 노즐 방향 제어를 통해 능동적으로 자세 제어가 가능한 부상 플랫폼에 관한 것이다. 이를 위해 본 발명은 추력에 의해 부상하는 플랫폼 하우징; 상기 플랫폼 하우징에 탑재되며, 추력 공급원으로부터 추력원을 공급받아 노즐로 추력원을 배출함에 따라 추력을 발생시키는 가변 쓰러스터; 및 수신한 상기 플랫폼 하우징의 자세 정보 및 기동 정보 중 적어도 하나를 기초로 하여 상기 가변 쓰러스터에 구비되는 쓰러스터 밸브의 개폐와, 상기 추력원을 배출하는 상기 가변 쓰러스터의 노즐 방향 및 노즐 면적의 제어 중 적어도 하나를 제어하는 제어부;를 포함한다.