Younkoo Jeong

A ciliary motion based 8-legged walking micro robot using cast IPMC actuators

In this paper, we present a micro robot using IPMC (Ionic Polymer Metal Composite) actuators. The IPMC actuator usually has been fabricated with commercially available ion-exchange polymer with the typical thickness of 100-300 /spl mu/m. By the casting of liquid ion-exchange polymer solution, the thickness of the IPMC actuator could increase up to a few millimeters. Based on the casting method, we could achieve the IPMC actuator that has larger stiffness and produces more generative tip force than the IPMC actuator fabricated with the commercially available solid ion-exchange polymer. A ciliary type 8-legged micro robot using the casting based IPMC actuators is constructed. The ciliary type 8-legged micro robot is 6.5 cm in length and 4.2 cm in width, and 1.5 cm in height and the total weight is 4.4 g with the actuators installed. The IPMC actuators used in this robot have a dimension of 20 mm in length, 4 mm in width and 1.15 mm in thickness. The input voltage to the IPMC actuator is set to /spl plusmn/4 V and the frequencies to the IPMC actuator is varying from 0.2 Hz to 1.0 Hz; with the increment of 0.2 Hz. The walking speed of the micro robot is changed from 3 mm/min to 17 mm/min with the variation of the frequencies.

A ciliary based 8-legged walking micro robot using cast IPMC actuators

We have proposed a prototype model of walking micro robot using IPMC (Ionic Polymer Metal Composite) actuators. The stiffness of IPMC actuator is a key parameter to implement a walking robot. Therefore, the casting process is developed to increase the stiffness of the actuator by controlling thickness of ion-exchange polymer film. The process of fabricating a solid film front liquid state of ion-exchange polymer is difficult since any process parameter and handling material are not disclosed and has to be set by trial and error. The bending characteristics and generative tip force of IPMC actuator under variation of thickness and length of the actuator and voltage input are investigated. Also, mechanical model is derived to predict the generative tip force and displacement of IPMC actuator according to the variation of thickness. With cast film based IPMC actuators, a ciliary type 8-legged micro robot, which can be operated in aqueous surroundings like inside of human body, is constructed and tested. The robot shows good reliability and can reach up to 17 mm/min in speed.

A locomotive mechanism for a robotic colonoscope

The increasing trend towards low fiber, high fat diets is leading to increasing pathology in the colon. Colonoscopy is a dexterous skill for doctors to perform and the procedure is painful to the patient. In this paper, we propose a new and simple locomotive mechanism that can be propelled by elliptic motion of multi legs. It has several legs that have constant phase difference to each other and are disposed along the upper and lower ends of the body. In order to evaluate the performance of the locomotive mechanism, we carried out simulations of moving characteristics and experiments in several environments including the colon of a pig.

Functional colonoscope robot system

Colonoscopy is an important medical procedure for the diagnosis of various diseases, such as cancers in the colon and rectum. However, it requires a lot of time for a doctor to acquire dexterous skills necessary to perform successful colonoscopy. Moreover, for many patients, conventional colonoscopy simply takes long time. Therefore, some studies on the development of autonomous and more convenient colonoscopes are carried out. In this paper, we propose a functional colonoscope robot system that has a locomotive function with a hollow body, a steering system, and other basic functions of typical conventional colonoscope systems. The concept and each component of the functional colonoscope system are described in this paper. In order to evaluate the functional performance of the colonoscope robot, we carried out in-vitro and in-vivo tests.

A wearable robotic arm with high force-reflection capability

Many exoskeletal robotic arms have been developed for teleoperation having force reflection. They can measure an operators arm motion and apply reactive force to the operator as well. Previous research has emphasized control performance of motion tracking and force reflection mainly but ignored how comfortable an operator feels, that is, issues of human wearability. Most robotic arms are heavy and give an operator excess fatigue during the teleoperation. We propose a robotic arm that satisfies high wearability and high force-reflection simultaneously. In order to accomplish these two objectives, the proposed arm has a parallel mechanism, one for a forearm and the other for a brachium. The parallel mechanism has an analogy to human muscular structure in which many extensors and flexors interact with each other and generate torque. The prismatic joints in the parallel mechanism act as virtual human muscles and determine joint torque by contraction and relaxation. The configuration of the prismatic joints enhances human wearability because all the joints are placed on the circumference of cylinders. Consequently, this circular configuration distributes internal force over an arm and thus contributes to reduce human fatigue during operation. In addition, the robotic arm does not make any singularity in its kinematics. The kinematic parameters in the robotic arm are selected to maximize the operators workspace while considering performance of force reflection.

Smart colonoscope system

As changing the eating habit to low fiber and high fat diet, the pathology in the colon is growing up annually. Colonoscopy is an important medical procedure for the diagnosis of various diseases like cancer in the colon and rectum. But it requires much time for doctors to acquire a dexterous skill to perform the operation of colonoscope and the procedure is painful and long to the patient in many cases. Therefore, some studies on the development of autonomous and more convenient colonoscope are carried out. In this paper, we propose a smart colonoscope system that has the locomotive function, active camera system, and human-friendly user interface besides the basic functions of the conventional colonoscope system. Doctors will be able to concentrate on the diagnosis itself with this system. The dexterity required to doctors and the pains imposed to patients will also be reduced with this system. The concept and each component of the smart colonoscope system are described in this paper. We carried out in-vitro test to evaluate its validity.

Design and control of a wearable robot

The concept of wearability will be recognized very important in future robotics as in computer science. There is a strong possibility that wearable robots suggest a new direction for human-robot interaction. We propose RoboWear, a robot that an operator wears on his arm. It can be used to amplify human power, to control a remote robot dexterously, to interact with humans in virtual environment. It has 7 DOF. Based on the anatomical analysis of a human arm and the distribution of multiple DOF over the space, authors designed a wearable robot with a hybrid structure consisting of two parallel manipulators and three separate joints. An operator wearing the robot arm can move around freely, because this robot is designed to have its base supported at the shoulder part of the operator. The total weight of the proposed robot arm is approximately 4 kg. Pneumatic actuators are used to reduce the total weight of the robot to improve compliance with human motion and to generate high reactive forces. The feasibility of the wearable robot is demonstrated by examining the control performance and by incorporating the wearable robot with virtual environment.

Functional Colonoscope Robot System

Colonoscopy is an important medical procedure for the diagnosis of various diseases like cancers in the colon and rectum. But it requires a lot of time for a doctor to acquire dexterous skills necessary to perform successful colonoscopy. Moreover, to many patients, conventional colonoscopy simply takes too long time. Therefore, some studies on the development of autonomous and more convenient colonoscope are carried out. In this Paper, we Propose a functional colonoscope robot system that has a locomotive function with a hollow body, a steering system, and other basic functions of typical conventional colonoscope systems. The concept and each component of the functional colonoscope system are described in this paper. In order to evaluate the functional performance of the colonoscope robot, we carried out in -vitro and in-vivo tests.

Locomotion Mechanism Using a Combination Cam with Multi-Phases

Robots that can move along the narrow and rough tube are very important as the request for the inspection increases. It is necessary for the inspection robots to have a capability to move successfully at even overturned situation and have a simple mechanism to reduce the unexpected failure possibility fer the successful completion of the given mission. Through this paper, the authors propose a novel and simple mechanism using a combination cam device to generate the locomotive motion of multi-legs. This robot uses one DC motor and one combination cam shaft to generate the locomotive motion and can move rough tubes without failure even at the overturned situation. The robot also shows enough fragging force fer the connected line that is very important for a wired inspection robot. Kinematics analysis to design the specification of the robot will be followed and several applications show this robot`s potential capabilities.