Donghwa Jeong

OrigamiBot-I: A Thread-Actuated Origami Robot for Manipulation and Locomotion

This paper presents OrigamiBot-I, a thread-actuated origami robot, to demonstrate a physical application of an origami design for robotic manipulation and locomotion. The selected design can generate twisting and bending motions by pulling, pushing, or torsional force applied to the origami structure. Thread-based actuation also enables various shapes and motions by using different numbers of threads and routing them through different paths. The kinematics for each twisting and bending motions based on estimated parameters is derived. To evaluate potential use of origami for real-world applications and identify structural weaknesses, preliminary stiffness and durability testing was conducted. For physical demonstrations of robotic manipulation and locomotion, OrigamiBot-I was equipped with four independently-routed threads, where each thread is controlled by a geared DC motor. The robot successfully demonstrated its simple manipulation and locomotion capabilities.

TaG-Games: Tangible geometric games for assessing cognitive problem-solving skills and fine motor proficiency

This paper presents Tangible Geometric Games (TaG-Games) as a novel play-based assessment tool for measuring cognitive problem-solving skills and fine motor proficiency. TaG-Games are based on sensor-integrated geometric blocks (SIG-Blocks) and an interactive graphical user interface providing a means for real-time and remote monitoring of a player through wireless communication between the blocks and a host computer. The data made available by employing TaG-Games includes: 1) accelerations, 2) time at each stage of assembly completion, 3) total completion time for each quiz, and 4) correctness of each assembly step. In addition, the user interface displays the real-time assembly configuration of the blocks. As a computational method for analyzing complexity associated with geometric play, a quantitative measure of play complexity is defined based on an information-theoretic approach. The validity of the sensors integrated in each SIG-Block (an accelerometer and optical sensors) is evaluated for measuring tilt angles and detecting assemblies between the blocks.

Design and analysis of an origami-based three-finger manipulator

This paper describes a new robotic manipulator with three fingers based on an origami twisted tower design. The design specifications, kinematic description, and results from the stiffness and durability tests for the selected origami design are presented. The robotic arm is made of a 10-layer twisted tower, actuated by four cables with pulleys driven by servo motors. Each finger is made of a smaller 11-layer tower and uses a single cable directly attached to a servo motor. The current hardware setup supports vision-based autonomous control and internet-based remote control in real time. For preliminary evaluation of the robots object manipulation capabilities, arbitrary objects with varying weights, sizes, and shapes (i.e., a shuttlecock, an egg shell, a paper cub, and a cubic block) were selected and the rate of successful grasping and lifting for each object was measured. In addition, an experiment comparing a rigid gripper and the new origami-based manipulator revealed that the origami structure in the fingers absorbs the excessive force applied to the object through force distribution and structural deformation, demonstrating its potential applications for effective manipulation of fragile objects.

SIG-Blocks

This paper presents the SIG-Blocks system developed for automated cognitive assessment via tangible geometric games (TAG-Games). Computerized game administration and real-time cognitive and behavior assessments were realized by wireless self-synchronization in communication, decentralized hybrid-sensing, assembly and motion detection, and graphical visualization. The measurable performance data included time and accuracy at each manipulation step, overall speed of manipulative motions, and the total number of rotational motions. For preliminary evaluation, three types of TAG-Games were designed: TAG-GameA for assembly, TAG-GameS for shape matching, and TAG-GameM for memory. As a part of the game design, a computational measure of play complexity was defined for each TAG-Game based on the geometric properties and the number of blocks in the item. An evaluation with 86 participants assessed both reliability of the TAG-Game items using split-half and test-retest reliability tests and validity of the proposed complexity measures by comparing the results with three subtests of the Wechsler Adults Intelligence Scale 4th Edition (WAIS-IV), i.e. Block Design (BD), Matrix Reasoning (MR), and Digit Span (DS). The high reliability coefficients showed that TAG-Games were reliable. Regarding validity, correlations were found between TAG-GameA and BD and between TAG-GameS and MR. Behavioral analysis also showed that the TAG-Game performance was positively correlated with the manipulation speed, but not correlated with the total number of rotations applied to the blocks. A new tangible game technology, called SIG-Blocks, is presented.TAG-Games, using SIG-Blocks as game control, are designed for automated cognitive assessment.Performance data in TAG-Games were correlated with selected standardized measures.SIG-Blocks and TAG-Games enable automated, remote assessment of cognitive skills.

Origamibot-II: An amphibious robot with reconfigurable origami wheels for locomotion in dynamic environments

This paper presents a mobile robot with reconfigurable origami wheels, called OrigamiBot-II. The origami wheels, based on the twisted tower design, can contract and extend the width and therefore suitable for amphibious locomotion in an unknown, possibly dynamic, environment. The mechanical design focused on achieving locomotion on various types of ground and water surfaces. To establish wireless communication between the robot and a remote base or another robot, radio frequency (RF) based techniques were investigated and tested for both ground and water environments. The locomotion performance of Origamibot-II was evaluated in two ways: simulations using Gazebo integrated with Robot Operating System (ROS) and physical experiments on various types of surfaces. The simulations showed that the robot moves faster with contracted wheels on a smooth surface than with extend wheels, while expanded wheels provides more traction on a rugged terrain, such as asphalt, than contracted wheels. Physical experiments supported the simulation results and further demonstrated the robot’s amphibious locomotion capability by successfully maneuvering on a variety of ground environments and water surfaces.Copyright

Distributed Communication and Localization Algorithms for Homogeneous Robotic Swarm

Swarm robotics aims to achieve physical flexibility, overall system robustness, and enhanced reliability and efficiency by employing a group of autonomous robots for collective task performance. Achieving collective performance by individual robots with limited sensing, processing, and communication capabilities, however, faces several technical challenges, such as difficulties in establishing reliable communication and decentralized control among the robots. This paper presents the following wireless communication algorithms that can be applied to homogeneous swarm robots: (1) infrared-based short-distance communication between the adjacent robots using a self-synchronization technique; and (2) long-distance communication and localization based on distance measurement using radio signals. In addition, two decentralized global shape formation algorithms for homogeneous swarm robots are presented for simulating dispersion and line formation collectively achieved by homogeneous swarm robots.

InchBot: A novel swarm microrobotic platform

Collective behavior in swarm robotics explores various scenarios involving many robots communicating, sensing, and running simultaneously. This strategy aims to reduce the time and energy required and to improve the efficiency of completing complex tasks which are typically difficult to accomplish individually. This paper presents InchBot, a novel swarm microrobotic platform, which is highly modular, rechargeable, and capable of sensing and communicating with each other wirelessly. InchBot features a new stackable hardware structure allowing customization in the embedded sensors and a novel flexible wheel design suitable for omnidirectional motions. A detailed analysis on the deformation characteristics of the flexible spoke wheels due to centrifugal force was performed using the finite element method. Preliminary experiments demonstrated the utility of flexible spoke wheels for generating forward, diagonal, and turning motions.

DESIGN AND EVALUATION OF A MULTI-SENSOR UNIT FOR MEASURING PHYSIOLOGICAL STRESSORS OF MEDICAL TRANSPORT

Patients who undergo inter-hospital transfer experience increased relative mortality, ranging from 10 to 100% higher than non-transferred patients. The high-cost, increased risk of complications and poor outcomes of transferred patients warrant the critical examination of potential causes. One of the major causes may be the external stressors that patients are exposed to during medical transport. To realize simultaneous measurements of external stressors, we developed a multisensor unit for measuring vibration, noise, ambient temperature, and barometric pressure. For preliminary evaluation, the sensor unit was tested on 29 medical transports, 11 air transports by a helicopter and 18 ground missions by an ambulance. The average whole-body vibration for each air and ground transport was calculated at 0.3510m/s 2 and 0.5871m/s 2