Optimizing the initial angle of the shoulder’s base frame is crucial for defining the workspace and enhancing the manipulation performance of humanoid robotic arms. Previous studies primarily emphasized geometric analyses, neglecting dynamic factors, which limits their practical applicability. This study presents a multi-metric optimization framework to enhance the dynamic performance of humanoid robotic arms by optimizing the shoulder’s initial angle. We formulate a cost function that incorporates torque efficiency, energy consumption, and overload ratio, utilizing the differential evolution (DE) algorithm for optimization. Furthermore, to address the limitations of conventional geometric workspace analysis, we introduce the concept of effective workspace, integrating dynamic constraints to quantitatively evaluate the effects of optimized shoulder angles. We validate the proposed framework in a hybrid simulation environment combining MuJoCo and RBDL, using the KIST humanoid and Unitree G1 robotic arms. Experimental results confirm that the optimized shoulder angles enhance torque distribution, expanding the effective workspace by 18.4% and 3.78% for the KIST and Unitree G1 robotic arms, respectively. These findings demonstrate that the proposed optimization framework enhances manipulation and dynamic performance as well as energy efficiency and system reliability, contributing to advancements in humanoid robotic arm design.

EtherCAT has been widely adopted in industrial automation and motion control owing to its real-time performance and flexible topology. However, an EtherCAT network with devices from different vendors requires extensive software modification which eventually increases development costs and effort. To address this issue, this paper presents a real-time control architecture focusing on a software-defined approach to easily reconfigure EtherCAT devices with minimal user intervention. This is achieved by simplifying the integration of EtherCAT slaves while exposing required parameters in a configuration interface through an API based on open-source EtherCAT master. We also provide a real-time variation of the POSIX library for a hard real-time multi-tasking environment considering task synchronization. Moreover, the real-time publish-subscribe protocol is also utilized to ensure seamless communication with devices outside of the EtherCAT network. To validate feasibility, practical example involving control of multi-axis robots and real-time performance analysis has been conducted.

The COVID-19 pandemic has caused a global public health crisis, leading to increased costs for operating essential quarantine facilities and risks of infection for medical staff. To address these issues, we have developed a non-contact delivery robot, UTD-pro, that can deliver food and supplies to patients in an isolated residential treatment center. In case of emergency situations such as communication failure with the control system or malfunction of specific modules, the noncontact delivery robot should be able to perform commands robustly or return home. Otherwise, as before, medical staffs may have to enter the high-risk environment again. In this paper, we propose a flexible and robust remote control system and a robot task management system that enables the robot to execute commands correctly. Our robot task manager allows for autonomous task execution with a single command from the remote control system. Each robot task operates independently, allowing users to change task plans flexibly during robot operation. The sensor data communication and task execution communication processes are also independent, preventing any issue in one process from affecting the other. By applying our system to the robot, we conducted a long-term delivery experiment for a total of 7.723km for 79 days, and achieved 125 successes out of 149 trials. This experiment proves that our system can lead to stable delivery processes and contribute to the high reliability of the control system and the robot task manager.

We develop a miniature suction-gripper with the goal to realize the novel robotic surgical instrument that can grip slippery and flexible peripheral nerves. In developing the instrument, we place a priority on devising the method that can robustly grip the nerve bundles during the surgical operation for the peripheral nerve. Also, we concentrate to investigate the working principle being able to minimize nerve damages that might be caused when manipulating the nerve. In this study, as the most suitable method to achieve the goal, we scheme to utilize the suction mechanism. Because it can non-invasively grip the nerve based on negative pressure, no external force is applied to the nervous tissues. Therefore the peripheral nerve can be manipulated without serious nerve damage (e.g. crush injury and stretch injury). To improve the gripping ability of the proposed suction gripper, two different types of microneedle arrays are applied to the suction-tips: passive-microneedle (PMN) arrays and active-microneedle (AMN) arrays. Since the most outer membrane of the nerve can be anchored by the penetrated PMN and AMN, the gripper can grip the nerve more robustly. The designed suction-gripper is fabricated as a functional prototype, and its working performances are assessed with in-vitro and in-vivo animal experiments. The experimental results well demonstrate the practical effectiveness of the proposed method and its applicability to the neurosurgical robot for the peripheral nerve.

In this paper, we present KULEX-hand, a novel underactuated hand exoskeleton for grasping power assistance for patients having a partially paralyzed hand or the elderly with weakened muscle strength. This mechanism consists of an underactuated finger for grasp motion generation, a spherical four-bar linkage for power transmission, and a passive thumb link with a flexure hinge structure. Based on the natural closing motion of the human index finger, the motion generation linkage was synthesized as a planar five-bar in which two input links were coupled with a four-bar linkage. Therefore, after contact occurs on the proximal link, the synthesized linkage can mimic the grasping motion of the human middle and distal phalanges. The kinetoelastic relation of the underactuated finger was derived using the theory of screws. Based on this relation, guidelines were proposed for selecting the springs for achieving a stable pinch grasp. A prototype was designed, and the naturalness of motion was evaluated from an experiment with five subjects.

This paper presents preliminary results of a handheld device to assist the insertion of intra-fascicular planar electrodes into a peripheral nervous system. The developed device consists of two units, a nerve holder and an electrode inserter. We introduce design considerations, features, and underlying mechanisms of the device. User tests and animal experiments show that users can easily and accurately adjust the insertion position and direction of nerve electrodes while manipulating the device in 3D, and that planar electrodes are successfully inserted into sciatic nerves of rats. We hope that the proposed device will help neural engineering researchers and scientists to simplify the surgical process and produce consistent experimental results.

This paper presents a comprehensive study on the design and implementation about 2-DOF decoupled kinematic actuator module based on the parallel structure with a high mechanical stiffness. The basic structure of 2-DOF decoupled kinematic actuator module has two motion units. Since one motion unit can be moved in only one direction, various applications are available and it can solve the parasitic motion fundamentally. The two motion units also have fine motion and coarse motion respectively. Besides it can be variously modified based on how the actuators are connected. Then the hardware of 2-DOF decoupled kinematic actuator module is implemented with one actuator and two additional locking devices. And the performance of the hardware will be evaluated by experimental system.

Physical size of semiconductor components has been reduced and device density has become increased especially during for last years. As a result of this the use of various high precision manipulatable robot systems becomes norm in the industry. Normally the high precision robot system consists of precision staging system, small scale end-effector system, and highly sensitive autonomous sensing system. One of the most popular micromanipulation tasks might be handling of micro-scale objects on a surface. Although many functional aspects and constraints should be considered when the system is constructed, a key concern for the system design is level of dexterity of the manipulator especially when size of the objects to be handled and spatial resolution of the manipulator become smaller than micron or nano scale. And stiction effect has appeared since a micro-contact mechanics phenomena affects more primarily than inertial force in the high precision robot system. Thus a theoretical study has to be developed on a micro-contact mechanics phenomena. In this paper, the organized system is equipped with an omnidirectional accessible manipulation system with a new visual feedback system. Thanks to the enhanced dexterity of the system, in this paper, microparticle stiction problems that could happen to most of small object handling also can be resolved.