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.

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.