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.

In this paper, we have developed a protection module for Light Detection and Ranging (LiDAR) sensors used in outdoor unmanned vehicles. Bio-inspired wiping motion was figured to have more efficient and excellent wiping performance than conventional cleaning methods for LiDAR sensors. An water wiping experiment confirmed that the finger wiping motion removed 35% more water than the translational wiping motion. Also, the theoretical analysis for the existence of an optimal rotational speed at maximum wiping performance was verified to be consistent with the experiment. The LiDAR distortion experiment results demonstrated no data distortion, showing an average error of up to 0.40% for detecting obstacles even when the acrylic cover rotates. Finally, a contamination protection experiment was conducted for water, powder, soil, and mud. As a result, although there was a change in the number of pointcloud and a decrease in the intensity of the sensor data after contamination, it was validated that the number of pointclouds and average intensity of data could be restored to at least 97% and 67% after being cleaned.

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.

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 "GripFlexer" based 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.

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.

This study proposes a modular Multi-axis Elastic Actuator (MAEA) for legged robots that can effectively cope with impacts that may occur during dynamic maneuvering. MAEA has multi-axis compliance and can measure the torque without additional encoders. Therefore, effective impact resistance is possible with less volume and weight than conventional Series Elastic Actuators (SEA). The 6-axis stiffness analysis of paired-Crossed Flexural Hinge (p-CFH) is extended from small deformation to large deformation, and the accuracy is verified through Finite Element Analysis (FEA) and experiments. Based on the analysis, the torque of p-CFH is measured, and feedback torque control is also performed. Finally, the robot leg was constructed with MAEA, and the multi-axis impact resistance performance of MAEA was demonstrated by analyzing the applied impact during landing experiments at various angles.

In our daily life, when a small amount of sweat or water forms on a person's hand, we can empirically feel that the friction force of the hand increases, and the objects are gripped well. However, if sweat or water forms heavily, we can feel the friction decrease when holding an object. In this study, we analyzed the degree to which fingerprints and sweat present on a person's hand can affect the friction force between the hand and the gripping object. We fabricated an anthropomorphic robot hand with a fingerprint structure to set up an environment similar to that of the human hand, and performed object-holding and friction-change experiments by changing the amount of sweat to verify that this phenomenon can be applied to a robot hand. Furthermore, we for the first time proposed and developed a variable friction system using fluids and microstructures to solve the difficulty of anthropomorphic robot hand force control. By applying the manufactured variable friction system and performing an active friction control performance test and an object grip test of the robot hand, we validated that the fingerprint and sweat of a human hand can affect the grip of an actual object.

Recently, diverse research has actively been conducted to control the posture of jumping robots using an inertial tail mechanism. However, the inertial tail mechanism has a high probability of collision with obstacles. In this study, a momentum wheel mechanism is proposed to achieve the same attitude control performance while reducing the volume occupied by the inertial tail mechanism. To verify the performance of the momentum wheel mechanism, we proposed a jumping robot with a momentum wheel mechanism and performed a dynamic analysis, simulation, and experiments on a jumping robot with a momentum wheel mechanism. In addition, it has been demonstrated that the momentum wheel mechanism can contribute to control of the body angle of the jumping robot. As a result, the momentum wheel mechanism can enhance the stability of the jumping robot more than the tail mechanism, and the momentum wheel mechanism contributes to the attitude control of the body angle, which allows the jumping robot to perform continuous jumping.