Joo Hyung Kim

The purpose of this research is the development of a soft skin module with a built-in airtight cavity in which air pressure can be sensed. A pressure feedback controller is implemented on a robotic system using this module for contact sensing and gentle grasping. The soft skin module is designed to meet size and safety criteria appropriate for a toy-sized interactive robot. All module prototypes are produced using a muti-material 3D printer. Experimental results from collision tests show that th

We develop a reconfigurable legged robot, named Snapbot, to emulate configuration changes and various styles of legged locomotion. The body of Snapbot houses a microcontroller and a battery for untethered operation. The body also contains connections for communication and power to the modular legs. The legs can be attached to and detached from the body using magnetic mechanical couplings. In the center of this coupling, there is a multi-pin spring-loaded electrical connector that distributes pow

This paper gives an overview of the development of a novel biped walking machine for a humanoid robot, Roboray. This lower-limb robot is designed as an experimental system for studying biped locomotion based on force and torque controlled joints. The robot has 13 actuated DOF and torque sensors are integrated at all the joints except the waist joint. We designed a new tendon type joint modules as a pitch joint drive module, which is highly back-drivable and elastic. We also built a decentralized

Using nitrogen and carbon dioxide as cushion gases can bring economic profit due to their cheap costs. However, the different properties of these gases cause differences in behavior when operating in underground gas storage (UGS). In particular, the mass density of nitrogen gas is similar to methane, while carbon dioxide is much heavier than methane in reservoir conditions. These differences cause loss of inert gas or productivity to vary. From this perspective, it is crucial to analyze the beha

Biped robots are inherently hybrid systems due to their intermittent, switching dynamics resulting from foot/ground impacts. It is well known that stable (passive) limit cycles for such mechanisms can be induced on shallow slopes without actuation. Most studies of passive dynamics to date have considered point or curved feet. In this paper, we consider passive bipeds with fixed flat feet. We study heel and toe rocking motions and the effect of relative foot length on the passive limit cycles. We

We propose a balancing control framework for a torque-controlled biped robot, Roboray. Roboray has two 6 DOF legs and torque sensors are integrated at all the leg joints. It has a new cable-driven joint module as a pitch joint drive, which is highly back-drivable and elastic. Using these hardware characteristics, we propose a new balancing control algorithm. This algorithm is the combination of gravity compensation, virtual gravity control and damping control. A friction compensation technique i

BACKGROUND: This study examined alcohol consumption and sexually transmitted disease risk behavior as related to prostitute visits and sex partner mix among male Korean university students in 1993 to 1994. METHODS: Questionnaires were completed by a representative sample of 1103 university students in Seoul. Lifetime sexually transmitted disease risk behavior was categorized as none, only one, and multiple sexual experiences with prostitutes, whereas risk according to partner mix was classified

This paper presents a novel robotic arm system, named PAPRAS (Plug-And-Play Robotic Arm System). PAPRAS consists of a portable robotic arm(s), docking mount(s), and software architecture including a control system. By analyzing the target task spaces at home, the dimensions and configuration of PAPRAS are determined. PAPRAS's arm is light (less than 6kg) with an optimized 3D-printed structure, and it has a high payload (3kg) as a human-arm-sized manipulator. A locking mechanism is embedded in th

We have developed a toy sized humanoid robot with soft air-filled modules on its links which sense contact and protect the robot and any interacting humans from damaging collisions. This robot, meant for robust physical interaction, is required to endure contact with children in the form of hugs and other playful interactions. It is therefore necessary to quantify the forces exerted during these interactions so that robots can be designed to both withstand these forces, as well as interact safel