Youngmok Yun

University of Texas at Austin | UT · Department of Mechanical Engineering

We have developed a one-of-a-kind hand exoskeleton, called Maestro, which can power finger movements of those surviving severe disabilities to complete daily tasks using compliant joints. In this paper, we present results from an electromyography (EMG) control strategy conducted with spinal cord injury (SCI) patients (C5, C6, and C7) in which the s...

Introduction: Impaired coordination within the shoulder complex is a frequent symptom in post-stroke survivors. However, most devices that have undergone clinical trials are unable to actively assist the full movement of the shoulder girdle. Purpose: In this study, we aim to evaluate the safety of the Harmony robot in post-stroke rehabilitation and...

In this paper, we address two of the most important challenges in development and control of assistive hand orthosis. First, supported by experimental results, we present a method to determine an optimal set of grasping poses, essential for grasping daily objects. Second, we present a method for determining the minimal number of surface EMG sensors...

We present an exoskeleton capable of assisting the human thumb through a large range of motion. Our novel thumb exoskeleton has the following unique features: (i) an underlying kinematic mechanism that is optimized to achieve a large range of motion, (ii) a design that actuates four degrees of freedom of the thumb, and (iii) a series elastic actuat...

We present a novel statistical model based control algorithm, called Control in the Reliable Region of a Statistical model (CRROS). First, CRROS builds a statistical model with Gaussian process regression, which provides a prediction function and uncertainty of the prediction. Then, CRROS avoids high-uncertainty regions of the statistical model by...

Rehabilitation of the hands is critical for the restoration of independence in activities of daily living for individuals exhibiting disabilities of the upper extremities. There is initial evidence that robotic devices with force-control-based strategies can help in effective rehabilitation of human limbs. However, to the best of our knowledge, non...

Training coordinated hand and wrist movement is invaluable during post-neurological injury due to the anatomical, biomechanical, and functional couplings of these joints. This paper presents a novel rehabilitation device for coordinated hand and wrist movement. As a first step towards validating the new device as a measurement tool, the device tran...

Many robotic applications need an accurate, robust, and fast estimation of finger pose. We present a novel finger pose estimation method using a motion capture system. The method combines a system identification stage and a state tracking stage in a unified framework. The system identification stage develops an accurate model of a finger, and the s...

We present a novel statistical model-based control algorithm, called Control in the Reliable Region of a Statistical Model (CRROS). A statistical model is unreliable when its state passes into a region where training data is sparse. CRROS drives the state away from such an unreliable region while pursuing the desired output by taking advantage of t...

This paper presents a systematic method for experimental characterization of Bowden cable friction. A novel Tension measurement method using a motion capture system and a spring is introduced. With The Tension measurement method, The effects of nine variables on friction are investigated. Experimental results show That i) a combination of 7×19 FEP-...

Purpose – The authors aim to propose a novel plane extraction algorithm for geometric 3D indoor mapping with range scan data. Design/methodology/approach – The proposed method utilizes a divide-and-conquer step to efficiently handle huge amounts of point clouds not in a whole group, but in forms of separate sub-groups with similar plane parameters...

Finger exoskeletons, haptic devices, and augmented reality applications demand an accurate, robust, and fast estimation of finger pose. We present a novel finger pose estimation method using a motion capture system. The method combines system identification and state estimation in a unified framework. The system identification stage investigates th...

A system for humanoid robot arm movement concerns about generating a human-like point-to-point (p2p) trajectory. For more than a decade, numerous systems have been devised and many of them were based on complex dynamical systems. In this paper, we introduce a simpler system, integrating support vector machine (SVM) learning model, which can achieve...

Autonomous outdoor navigation algorithms are required in various military and industry fields. A stable and robust outdoor localization algorithm is critical to successful outdoor navigation. However, unpredictable external effects and interruption of the GPS signal cause difficulties in outdoor localization. To address this issue, first we devised...

Odometry calibration is an essential step for successful navigation of any moving system because most of the control algorithms work based on odometry information. Odometry errors can be categorized as systematic and non-systematic errors. In this paper, a terminal iterative learning control (TILC) based odometry calibration method is proposed to c...

For a successful navigation, odometry calibration is an essential step because most of the control algorithms works based on odometry information. In odometry, two types of errors, namely, systematic and non-systematic error appear. In this paper, a terminal iterative learning control based odom-etry calibration method is proposed to calibrate syst...

Odometry calibration is a first and essential step to do for a successful navigation because most of control algorithms are based on odomety information. Odometry error can be categorized as systematic and non-systematic error. In this paper, we suggest a novel method to calibrate systematic error using inherent home positioning capability of home...