https://scholar.dgist.ac.kr/handle/20.500.11750/903 2026-04-04T09:44:25Z 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/20.500.11750/57890 Title: Development of a Modular Robotic Finger for Gripping Various Shaped Objects Author(s): Kim, Jisu; Cho, Jiman; Kang, Yeon; Lee, Changwha; Yun, Dongwon Abstract: With the introduction of the Fourth Industrial Revolution and the spread of smart factories, the demand for small-quantity batch production systems is rapidly increasing. As a result, the implementation of robotic gripper systems that can handle various objects is required. Until now, grippers have to be replaced or newly developed each time depending on the object to be gripped. In addition, conventional gripper systems require a picking system based on a sophisticated gripping plan to handle products with complex shapes. This requires the integration of vision and various sensor systems, which in turn increases the cost of the system and makes it challenging to apply it to real industrial sites. To solve this problem, we developed a robotic finger by applying the paired crossed flexure hinge (p-CFH) developed in our previous research. The p-CFH-based robotic finger is driven by an underactuated wire-driven method that can be controlled by a single motor and has compliance and shape adaptive features. It also has the advantage of being modularized, easy to install and replace, and easy to maintain. The proposed finger module has a tip force of about 0.58 kg and its impact absorption capacity has been experimentally verified. In addition, gripping experiments were conducted on a total of four objects with different characteristics, and successful gripping was confirmed. © 2024 IEEE. 2024-10-13T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57889 Title: GripFlexer: Development of hybrid gripper with a novel shape that can perform in narrow spaces Author(s): Kim, Donghyun; Choi, Sunghyun; Song, Bongsub; Song, Jinhyeok; Yoon, Jingon; Yun, Dongwon Abstract: In recent years, the role of robots across industries has become increasingly diverse, and they are now required to perform complex missions beyond simple repetitive tasks. However, robots used in confined spaces that humans cannot reach or in disaster field missions have challenges in performing various tasks due to their small size. In this study, we developed a compact hybrid gripper that fuses a multi-finger gripper and a jamming gripper to perform various tasks in a confined environment. Such a hybrid gripper can have both the strengths of a multi finger gripper that can perform various tasks and a jamming gripper that can effectively handle irregular small objects. In this study, we developed a hybrid gripper GripFlexerbased on theoretical analysis and confirmed its performance through experiments by taking the task of turning a circular doorknob, which is one of the most difficult tasks in disaster sites, as the final target task. We also confirmed that the two grippers of GripFlexer can interact by showing performance improvement effects when two grippers are operated simultaneously. © 2024 IEEE. 2024-10-15T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57888 Title: Development of a Throwbot with Shock Absorption Structure Author(s): Keum, Jaeyeong; Kim, Jaemin; Lee, Changgi; Lim, Seunghyun; Ju, Insung; Yun, Dongwon Abstract: In this study, a throwing robot equipped with an shock absorbing structure, utilizing paired-Cross Flexural Hinge (p-CFH) and an airbag, was fabricated and validated to assess the effectiveness of its impact absorption mechanism. This robot was developed in anticipation of situations where direct human intervention for life rescue would be challenging. Throwing robots can be broadly categorized into ball type, wheel type, and hybrid type. The hybrid type combines the advantages of both: the ease of throwing from ball type, due to its low air resistance coefficient, and the versatile mobility of the wheel type in diverse environments. However, hybrid type throwing robots are more vulnerable to external impacts due to the complexity of their internal structure, resulting in a lower maximum drop height compared to wheel type robots.To address these challenges, this research proposes a the Throwbot that combines the easy throwing capability of ball type with the obstacle overcoming ability of the wheel type, while also addressing the low free fall height drawback inherent in hybrid types. To achieve this, we developed a Throwbot with a ball to wheel transform structure, p-CFH mechanism, and airbag based impact absorption system. Additionally, materials were selected based on simulation results to refine the Throw-bot. The performance of the proposed robot was evaluated through various assessments, including free fall experiments and obstacle overcoming tests. Through this research, the proposed Throwbot effectively addresses the shortcomings of existing throwing robots, establishing a novel approach to throwing robot design. © 2024 IEEE. 2024-10-17T15:00:00Z