Yongkwun Lee

Development of bio-mimetic robot hand using parallel mechanisms

This paper describes a development of bio-mimetic robot hands and its control scheme. Each robot hand has four under-actuated fingers, which are driven by two linear actuators coupled. According to the study of the human hand, it is noted that coupled muscles (flexor and extensor muscle) generate the finger motion. Each fingertip can reach toward objects by curved surface workspace in 3D-space. The robot hand was designed considering the dexterity and the size suited for human tools and has tactile sensors equipped on the fingertips of each finger. The robot hand has 4 fingers with totally nine DOFs including two linear actuators and linkage knuckles. In the former part of this paper, the design of the robot hand is presented. And in the latter part of the paper, computational simulations are described. The simulations show the performance of the robot hand to manipulate tools of various shapes.

Micro hydraulic system using slim artificial muscles for a wearable haptic glove

Over the past few decades, various haptic gloves have been developed for use in virtual environments. The actuating systems for most existing haptic gloves require lots of external auxiliary equipment. Because of this, the motion of the user is restricted by the length of the electric wires or pneumatic tubes attached to this equipment. A compact actuation system, including related equipment, is thus indispensable for a wearable haptic glove to be truly effective. To resolve the problem of hampered motion and reach, a micro hydraulic actuating system was developed in this research. It was composed of a slim, flexible artificial muscle, a compact hydraulic module for actuating the muscle, and a micro pressure sensor for measuring without flux loss. The characteristics of the muscle were investigated for their control capacity. The step and sinusoidal responses were analyzed to evaluate the performance of the micro hydraulic system. Once these analyses were completed, a lightweight and compact actuation system was built incorporating a wearable haptic glove. By virtue of the developed micro hydraulic system, the wearable haptic glove was able to operate independently of any external equipment, and movement was completely free of any restrictions from wires or tubes.

Robotic automation system for steel beam assembly in building construction

In building construction, steel beam assembly has been considered as one of the most dangerous manual operations. In this paper, applying robotic technologies to the steel beam assembly task is discussed. Employing the robotic systems to automate such construction tasks gives the following advantages: saving construction time and cost, enhancing operators safety, and improving overall quality. The automated robotic assembly system presented in the paper consists of a robotic bolting device, a robotic mobile mechanism, and a bolting control system including human-machine interface. The robotic bolting device, which includes a bolting end-effector and a robotic manipulator, performs actual bolting operation. Utilizing the robotic mobile mechanism composed of a rail sliding boom mechanism and a scissors-jack type mobile manipulator, the robotic assembly system can be transported to a target position for bolting operation. The bolting control system plays a role of safely and efficiently operating the robotic assembly system employing a hole recognition system based on vision technology and a haptic based HMI (Human-Machine Interface) system. This paper includes the major components of the entire robot system that have been built and the future plans to integrate them.

Development of Automation System for Steel Construction Based on Robotic Crane

This paper deals with an automation system for steel construction based on a robotic crane. Employing an automation system for steel construction of high-rise buildings has following advantages: reducing risk factors in human operation, decreasing the construction cost, and shortening the construction period. The automated robotic crane system suggested in this paper consists of moving mechanism, robot manipulation system, and HMI (human machine interface). Moving mechanism is composed of boom, rail, and scissor-jack type manipulator. Using this mechanism, the robot manipulator can be located anywhere in CF (construction factory). The robot manipulation system is composed of a cabin and two robot arms. The cabin acts as a cockpit for the operator. The first robot arm has a bolting end-effector to assemble H-beams and the second robot arm has an alignment end-effector to align H-beams before assembling task. HMI system helps workers operate robot manipulators through a haptic device and a vision system. Also, it contains ITA (intelligent teaching agent) system that helps unskilled workers operate easily.

Design of a bolting robot for constructing steel structure

During the last decades, the automation for constructing a steel structure has been extensively studied. However, the bolting process is still remained as a manual work, and the human workers climbs the vertical steel beams on top of the high-rise steel structure in many construction fields. The manual bolting process is extremely dangerous and inefficient. To resolve this problem, a new bolting robot is developed in this research. The bolting robot composed of two parts, a posturing base and bolting grippers. The posturing base is specially designed to ensure the convenient posture to approach the bolting holes. The bolting gripper equips a bolting tool, and fastens the bolt with respect to a predefined torque. Some experiments ware conducted to evaluate the developed system, and it successfully carried out the automated bolting process.

Wearable haptic glove using micro hydraulic system for control of construction robot system with VR environment

Over the past few decades, various haptic devices have been developed in order to control various robot systems remotely. The actuating systems for most existing haptic devices including glove type require lots of external auxiliary equipment. Because of this, the motion of the user is restricted by the length of the electric wires or pneumatic tubes attached to this equipment. A compact actuation system, including related equipment, is thus indispensable for a wearable haptic device to be truly effective. To resolve the problem of hampered motion and reach, a micro hydraulic actuating system was developed in this research. It was composed of a slim, flexible artificial muscle, a compact hydraulic module for actuating the muscle, and a micro pressure sensor for measuring without flux loss. The characteristics of the muscle were investigated for their control capacity. Once these analyses were completed, a lightweight and compact actuation system was built incorporating a glove typed wearable haptic device. By virtue of the developed micro hydraulic system, the wearable haptic glove was able to operate independently of any external equipment, and movement was completely free of any restrictions from wires or tubes. The construction robot remotely controlled needs a compact haptic device as a motion controller for it and the haptic glove we developed makes it possible to control the motion of construction robot with easy.

Development of Bio-Machine Based on the Plant Response to External Stimuli

In the area of biorobotics, intense research work is being done based on plant intelligence. Any living cell continuously receives information from the environment. In this paper, research is conducted on the plant named descoingsii x haworthioides (Pepe) obtaining the action potential signals and its responses to stimulations of different light modes. The plant electrical signal is the reaction of plant’s stimulation owing to various environmental conditions. Action potentials are responsible for signaling between plant cells and communication from the plants can be achieved through modulation of various parameters of the electrical signal in the plant tissue. The modulated signals are used for providing information to the microcontroller’s algorithm for working of the bio-machine. The changes of frequency of action potentials in plant are studied. Electromyography (EMG) electrodes and needle-type conductive electrodes along with electronic modules are used to collect and transform the information from the plant. Inverse fast Fourier transform (IFFT) is used to convert signal in frequency domain into voltage signal for real-time analysis. The changes in frequency of the plant action potentials to different light modes are used for the control of the bio-machine. This work has paved the way for an extensive research towards plant intelligence.

An End-Effector Design for H-beam Alignment in High-Rise Building Construction

There have been active progresses in the construction of high-rise buildings since the robot and information technologies were applied to the construction industry. Although many techniques have been proposed for safe and efficient H-beam lifting and assembly, most of construction tasks are manually operated causing dangerous working environments. The objective of this study is to develop a robotic end-effector for fine H-beam alignment in high-rise building construction. The H-beam has a number of drilled holes so that bolts can go through to assemble the elements. Before the bolts are inserted to combine two H-beams, the bolt holes should be aligned with very tight tolerance. Otherwise, there is a potential for serious damage during the bolting process. In this study, an end-effector design that helps the H-beam alignment for bolting operation is proposed. Moreover, finite element analysis and computer simulations are conducted to evaluate the mechanism.

Development of Bio-machine based on the plant response to external stimuli

In the area of Bio robotics, intense research work is going on in plant intelligence. Any living cell continuously receives information from the environment. The plant electrical signal is the reaction of plants to the stimulation due to various environmental conditions. Action potentials are responsible for signaling between plant cells because they can be induced and transmitted rapidly within the plant tissue. Communication from the plants can be achieved through modulation of the amplitude, frequency change, and change in resistance and the rate of propagation of the electrical signal in the plant tissue. In this paper research is conducted on the plant signals and its response to various environments. The change of frequency of action potential signals in plant named Pepe (Descoingsii x hawothioides) under different light modes are studied. Electromyography (EMG) electrodes and Needle type conductive electrodes along with electronic modules are used to collect and transform the information from the plants. Analysis on the plant signal has been carried out. Inverse Fast Fourier transform (IFFT) is used to convert frequency to voltage signal. The change in frequency of the plant action potential signals to different light modes are used for the control of the Bio-machine. The present work paved an extensive research towards plant intelligence.

The Design of a Patient Transportation Robot's Lifting Arms Considering Comfort and Safety without the Presence of a Sheet

A transportation robots lifting arms have an effect on the comfort and safety of patients. Improved arms have been designed through dynamic and static analyses to increase safety if a sheet not present on the lifting arms. To design the lifting arms, experimentation is very helpful, however, it is difficult and dangerous to experiment on patients; therefore, a simple human model was made and used for the dynamic analysis. Through the dynamic analysis results, a safe width and comfortable location for the lifting arms were determined. The thickness was then determined by static analysis and optimum design. In addition, tests have been conducted to confirm comfort and safety by deploying the designed lifting arms onto a transportation robot.