Seung-Nam Yu

Development of human-robot interfacing method for assistive wearable robot of the human upper extremities

We suggest a human-robot interfacing method of a wearable robot for assistive human upper extremities. It connects the human and the robot with the multi-axis load-cell, and it measures the relative force between the human and the robot. The control system calculates the trajectory of end-effector using this force signal. In this paper, we verify the performance of proposed system through the motion of elbow E/F (extension/flexion), the shoulder E/F, and the shoulder Ab/Ad(abduction/adduction). We generated the command signal using the human-robot interfacing method so that a user would be able to operate the wearable robot of 6-DOF. And, we performed subsequent capability and force assistance experiments for performance verification of the proposed this method.

Development of a Walking Assistive Service Robot for Rehabilitation of Elderly People

In order to realize a welfare community, where elderly and disabled people can comfortably live a normal life, it is essential to develop various devices and systems, using cutting-edge science and technology. In particular, there is an urgent need for the development of a human-friendly robotic system that is flexible and adaptable enough to meet the needs of our aging population, and the needs of disabled people living within the community. For walking exercises several items of auxiliary equipment are required to help the roles of the lower limbs. For traditional walking auxiliary equipment, these can be divided into the parallel bar (with the bottom part adjusted), which supports the walker at four points, crutches, which supports the walker at two points, and the cane which supports the walker at only one point. The parallel bar consists of two bars secured at an appropriate height in parallel: it is the most stable form of walking auxiliary equipment. The walker uses them to help him or her to stand straight, and balance the body while walking exercises are undertaken. With support at four points, parallel bars generally give stability, but since they are not externally secured, falls are possible. Its shortcomings include that the user cannot walk fast, and may have difficulty in walking up a slope. Crutches and canes are more commonly used. These buttress the weight of the user, thereby assisting weakened legs and lessening the weight carried, (which may also reduce pain) to enable more natural walking. However, these traditional rehabilitation devices depend upon use by and adjustment with the upper limbs and upper body, so that the degree of weight support is inconsistent and immeasurable. Furthermore, the energy consumption required in using these devices is considerable. Equipment such as the orthopedic scooter, the bath bike, etc., reduces the energy consumption and provides a larger degree of freedom of movement. However, they do not satisfy the basic needs in terms of adjustment of supporting strength. BWS is an item of treatment equipment for rehabilitation exercises for patients with neurological damage. It was proposed in 1985 to assist the easy attainment of the natural walking pattern (L. Finch, 1991). In 1987, a cat that had its spine completely split was treated in a walking exercise program by using the weight support system repeatedly on a treadmill and it was then discovered that several aspects of walking in humans is similar to walking

Development of an underactuated exoskeleton for effective walking and load-carrying assist

Abstract This study proposed and developed an underactuated exoskeleton to support external load-carrying and partial assist for leg motion with level walking and ascending of slopes and stairs, which require positive energy generation. A strategy for active and passive joint combination are implemented on the underactuated exoskeleton, along with a quasi-passive mechanism to assist with vertical weight support and gait propulsion while minimizing hindrance to the wearer’s free motion. Further, muscle circumference sensors are directly matched with the active joint system, and insole sensors are applied to efficiently detect the wearer’s motion intension. Through experiments with the developed exoskeleton system, the considered performances were verified by analyzing the electromyography data from the rectus fremoris and gastrocnemius muscles while walking and ascending stairs. The developed underactuated exoskeleton can assist healthy people’s load-carrying and facilitate efficient ascension by utilizing the structural body weight support, leg swing, and lifting motion assist through motorized knee joints only. This kind of active joint minimization approach could be particularly helpful in field applications that require independent power sources such as batteries.

Design considerations of a lower limb exoskeleton system to assist walking and load-carrying of infantry soldiers

This paper describes the development of a wearable exoskeleton system for the lower extremities of infantry soldiers and proposes appropriate design criteria based on existing case studies. Because infantry soldiers carry a variety of equipment, the interference with existing equipment and additional burden of the exoskeleton support system should be minimized. Recent studies have shown that a user only needs to be supported in the gravitational direction when walking on flat terrain; however, active joints are necessary to support walking over rough and sloped terrain such as mountains. Thus, an underactuated exoskeleton system was considered: passive joints are applied to the hip and ankle joints, and active joints are applied to the knee joints to exploit the dynamic coupling effect of the link structure and muscular activation patterns when the user is going up and down stairs. A prototype of the exoskeleton system was developed and validated through a simple stair-climbing experiment.

ERGONOMIC ANALYSIS OF A TELEMANIPULATION TECHNIQUE FOR A PYROPROCESS DEMONSTRATION FACILITY

In this study, remote handling strategies for a large-scale argon cell facility were considered. The suggested strategies were evaluated by several types of field test. The teleoperation tasks were performed using a developed remote handling system, which enabled traveling over entire cell area using a bridge transport system. Each arm of the system had six DOFs (degrees of freedom), and the bridge transport system had four DOFs. However, despite the dexterous manipulators and redundant monitoring system, many operators, including professionals, experienced difficulties in operating the remote handling system. This was because of the lack of a strategy for handling the installed camera system, and the difficulty in recognizing the gripper pose, which might fall outside the FOV (field of vision) of the system during teleoperation. Hence, in this paper, several considerations for the remote handling tasks performed in the target facility were discussed, and the tasks were analyzed based on ergonomic factors such as the workload. Toward the development of a successful operation strategy, several ergonomic issues, such as active/passive view of the remote handling system, eye/hand alignment, and FOV were considered. Furthermore, using the method for classifying remote handling tasks, several unit tasks were defined and evaluated.

Development of Command Signal Generating Method for Assistive Wearable Robot of the Human Upper Extremity

This paper proposes command signal generating method for a wearable robot using the force as the input signal. The basic concept of this system pursues the combination of the natural and sophisticated intelligence of human with the powerful motion capability of the robot. We define a task for the command signal generation to operate with the human body simultaneously, paying attention to comfort and ease of wear. In this study, we suggest a basic exoskeleton experimental system to evaluate a HRI(Human Robot Interface), selecting interfaces of arm braces on both wrists and a weight harness on the torso to connect the robot and human. We develop the HRI to provide a command for the robot motion. It connects between the human and the robot with the multi-axis load-cell, and it measures the relative force between the human and the robot. The control system calculates the trajectory of end-effector using this force signal. In this paper, we verify the performance of proposed system through the motion of elbow E/F(Extension/Flexion), the shoulder E/F and the shoulder Ab/Ad (Abduction/Adduction).This paper proposes command signal generating method for a wearable robot using the force as the input signal. The basic concept of this system pursues the combination of the natural and sophisticated intelligence of human with the powerful motion capability of the robot. We define a task for the command signal generation to operate with the human body simultaneously, paying attention to comfort and ease of wear. In this study, we suggest a basic exoskeleton experimental system to evaluate a HRI(Human Robot Interface), selecting interfaces of arm braces on both wrists and a weight harness on the torso to connect the robot and human. We develop the HRI to provide a command for the robot motion. It connects between the human and the robot with the multi-axis load-cell, and it measures the relative force between the human and the robot. The control system calculates the trajectory of end-effector using this force signal. In this paper, we verify the performance of proposed system through the motion of elbow E/F(Extension/Flexion), the shoulder ElF and the shoulder Ab/Ad (Abduction! Adduction).

Virtual Sensor Verification Using Neural Network Theory of the Quadruped Robot

The sensor data measured by the legged robot are used to recognize the physical environment or information that controls the robot`s posture. Therefore, a robot`s ambulation can be advanced with the use of such sensing information. For the precise control of a robot, highly accurate sensor data are required, but most sensors are expensive and are exposed to excessive load operation in the field. The seriousness of these problems will be seen if the prototype`s practicality and mass productivity, which are closely related to the unit cost of production and maintenance, will be considered. In this paper, the use of a virtual sensor technology was suggested to address the aforementioned problems, and various ways of applying the theory to a walking robot obtained through training with an actual sensor, and of various hardware information, were presented. Finally, the possibility of the replacement of the ground reaction force sensor of legged robot was verified.

Equipment Layout Improvement for Large-Scale Hot Cell Facility Logistics

This study presents approaches to equipment layout improvement for a large-scale hot cell facility. First, the original facility layout and target process are introduced, including the basic information and specifications. Second, the flow of process materials is analyzed and the relationships are evaluated in detail using a “from-to chart” and a “relationship chart” for the original layout, and the logistics are simulated using the selected discrete event simulator to calculate the traveling distances of process materials handled by teleoperated material handling systems. Third, the original layout is modified using the total closeness rating (TCR), and the efficiency and usage of the material handling system are calculated and compared with the original case to evaluate the efficiency improvement of the modified layout. This modification process, which included load reduction, enabled those aspects of the material handling system that would need to be changed to be identified; these changes were suggested by a quantitative analysis of the logistics between each pair of stations and intuitive rearrangement based on charts and figures. These approaches could be an initial step in the large-scale hot cell design process, with future work to follow.

Manipulator Design Strategy for a Specified Task Based on Human-Robot Collaboration

Seungnam Yua, Seungwhan Suha, Woonghee Sonb,c, Youngsoo Kimb,d and Changsoo Hana a Dept. of Mechanical Eng., Hanyang University, 1271 Sa-3 dong, Sangnok-gu, Ansan, Kyeonggi-do, Korea b Dept. of Mechatronics Eng., Hanyang University, 1271 Sa-3 dong, Sangnok-gu, Ansan, Kyeonggi-do, Korea c Korea Institute of Industrial Technology, 1271-18 Sa-3 dong, Sangnok-gu, Ansan, Kyeonggi-do, Korea dMinistry of Education, Science and Technology, 77-6, Sejong-No, Jongno-Gu, Seoul, Korea

Development of Body-Weight-Support System for Walking Rehabilitation

As the population of elderly people and disabled people are increased, various demands for human welfare using robot system are raised. Especially autonomous rehabilitation system using robot could reduce the human effort while maintaining the its intrinsic efficacy. This study deals with mobile gait rehabilitation system which combined with BWS (Body Weight Support) for training of elderly and handicapped people who suffer the muscle force weakness of lower extremity. BWS which is designed by kinematic analysis of body lifting characteristics and walking guide system are integrated with main control system and wheeled platform. This mobile platform is operated by UCS (User Command System) and autonomous trajectory planning algorithm. Finally, through the EMG (Electromyography) signal measuring and its analysis for subject, performance and feasibility of developed system is verified.