Matching Items (10)
Filtering by
- All Subjects: robotics
- All Subjects: Exoskeletons
- Creators: Artemiadis, Panagiotis
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
- Resource Type: Text
- Status: Published
Description
This thesis focused on understanding how humans visually perceive swarm behavior through the use of swarm simulations and gaze tracking. The goal of this project was to determine visual patterns subjects display while observing and supervising a swarm as well as determine what swarm characteristics affect these patterns. As an ultimate goal, it was hoped that this research will contribute to optimizing human-swarm interaction for the design of human supervisory controllers for swarms. To achieve the stated goals, two investigations were conducted. First, subjects gaze was tracked while observing a simulated swarm as it moved across the screen. This swarm changed in size, disturbance level in the position of the agents, speed, and path curvature. Second, subjects were asked to play a supervisory role as they watched a swarm move across the screen toward targets. The subjects determined whether a collision would occur and with which target while their responses as well as their gaze was tracked. In the case of an observatory role, a model of human gaze was created. This was embodied in a second order model similar to that of a spring-mass-damper system. This model was similar across subjects and stable. In the case of a supervisory role, inherent weaknesses in human perception were found, such as the inability to predict future position of curved paths. These findings are discussed in depth within the thesis. Overall, the results presented suggest that understanding human perception of swarms offers a new approach to the problem of swarm control. The ability to adapt controls to the strengths and weaknesses could lead to great strides in the reduction of operators in the control of one UAV, resulting in a move towards one man operation of a swarm.
ContributorsWhitton, Elena Michelle (Author) / Artemiadis, Panagiotis (Thesis director) / Berman, Spring (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
This thesis focused on grasping tasks with the goal of investigating, analyzing, and quantifying human catching trends by way of a mathematical model. The aim of this project was to study human trends in a dynamic grasping task (catching a rolling ball), relate those discovered trends to kinematic characteristics of the object, and use this relation to control a robot hand in real time. As an ultimate goal, it was hoped that this research will aide in furthering the bio-inspiration in robot control methods. To achieve the above goal, firstly a tactile sensing glove was developed. This instrument allowed for in depth study of human reactionary grasping movements when worn by subjects during experimentation. This sensing glove system recorded force data from the palm and motion data from four fingers. From these data sets, temporal trends were established relating to when subjects initiated grasping during each trial. Moreover, optical tracking was implemented to study the kinematics of the moving object during human experiments and also to close the loop during the control of the robot hand. Ultimately, a mathematical bio-inspired model was created. This was embodied in a two-term decreasing power function which related the temporal trend of wait time to the ball initial acceleration. The wait time is defined as the time between when the experimental conductor releases the ball and when the subject begins to initiate grasping by closing their fingers, over a distance of four feet. The initial acceleration is the first acceleration value of the object due to the force provided when the conductor throws the object. The distance over which the ball was thrown was incorporated into the model. This is discussed in depth within the thesis. Overall, the results presented here show promise for bio-inspired control schemes in the successful application of robotic devices. This control methodology will ideally be developed to move robotic prosthesis past discrete tasks and into more complicated activities.
ContributorsCard, Dillon (Co-author) / Mincieli, Jennifer (Co-author) / Artemiadis, Panagiotis (Thesis director) / Santos, Veronica (Committee member) / Middleton, James (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / W. P. Carey School of Business (Contributor)
Created2014-05
Description
Walking ability is a complex process that is essential to humans, critical for performing a range of everyday tasks and enables a healthy, independent lifestyle. Human gait has evolved to be robust, adapting to a wide range of external stimuli, including variable walking surface compliance. Unfortunately, many people suffer from impaired gait as a result of conditions such as stroke. For these individuals, recovering their gait is a priority and a challenge. The ASU Variable Stiffness Treadmill (VST) is a device that is able to the change its surface compliance through its unique variable stiffness mechanism. By doing this, the VST can be used to investigate gait and has potential as a rehabilitation tool. The objective of this research is to design a variable damping mechanism for the VST, which addresses the need to control effective surface damping, the only form of mechanical impedance that the VST does not currently control. Thus, this project will contribute toward the development of the Variable Impedance Treadmill (VIT), which will encompass a wider range of variable surface compliance and enable all forms of impedance to be con- trolled for the first time. To achieve this, the final design of the mechanism will employ eddy current damping using several permanent magnets mounted to the treadmill and a large copper plate stationed on the ground. Variable damping is obtained by using lead screw mechanisms to remove magnets from acting on the copper plate, which effectively eliminates their effect on damping and changes the overall treadmill surface damping. Results from experimentation validate the mechanism's ability to provide variable damping to the VST. A model for effective surface damping is generated based on open-loop characterization experiments and is generalized for future experimental setups. Overall, this project progresses to the development of the VIT and has potential applications in walking surface simulation, gait investigation, and robot-assisted rehabilitation technology.
ContributorsFou, Linda Guo (Author) / Artemiadis, Panagiotis (Thesis director) / Lee, Hyunglae (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Many industries require workers in warehouse and stockroom environments to perform frequent lifting tasks. Over time these repeated tasks can lead to excess strain on the worker's body and reduced productivity. This project seeks to develop an exoskeletal wrist fixture to be used in conjunction with a powered exoskeleton arm to aid workers performing box lifting types of tasks. Existing products aimed at improving worker comfort and productivity typically employ either fully powered exoskeleton suits or utilize minimally powered spring arms and/or fixtures. These designs either reduce stress to the user's body through powered arms and grippers operated via handheld controls which have limited functionality, or they use a more minimal setup that reduces some load, but exposes the user's hands and wrists to injury by directing support to the forearm. The design proposed here seeks to strike a balance between size, weight, and power requirements and also proposes a novel wrist exoskeleton design which minimizes stress on the user's wrists by directly interfacing with the object to be picked up. The design of the wrist exoskeleton was approached through initially selecting degrees of freedom and a ROM (range of motion) to accommodate. Feel and functionality were improved through an iterative prototyping process which yielded two primary designs. A novel "clip-in" method was proposed to allow the user to easily attach and detach from the exoskeleton. Designs utilized a contact surface intended to be used with dry fibrillary adhesives to maximize exoskeleton grip. Two final designs, which used two pivots in opposite kinematic order, were constructed and tested to determine the best kinematic layout. The best design had two prototypes created to be worn with passive test arms that attached to the user though a specially designed belt.
ContributorsGreason, Kenneth Berend (Author) / Sugar, Thomas (Thesis director) / Holgate, Matthew (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This study presents quantification of ankle stability as affected by environmental conditions in two degrees of freedom (DOF) with three distinct analysis techniques. Additionally, this study presents gender-specific trends for comparison. Intuitively, ankle stability decreased in less stable environments with a negative simulated stiffness. Female subjects generally suffered a greater loss of stability in moderately and highly unstable environments. Both gender groups exhibited greater stability in the sagittal plane than the frontal plane across the entire range of simulated stiffness's. Outcomes of this study are useful in the design of controllers for lower extremity physically-interactive robotics, understanding situations in which the ankle is likely to lose stability, and understanding the strengths and weaknesses of unique analysis techniques.
ContributorsHanzlick, Harrison Patrick (Author) / Lee, Hyunglae (Thesis director) / Artemiadis, Panagiotis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
For the past two decades, advanced Limb Gait Simulators and Exoskeletons have been developed to improve walking rehabilitation. A Limb Gait Simulator is used to analyze the human step cycle and/or assist a user walking on a treadmill. Most modern limb gait simulators, such as ALEX, have proven themselves effective and reliable through their usage of motors, springs, cables, elastics, pneumatics and reaction loads. These mechanisms apply internal forces and reaction loads to the body. On the other hand, external forces are those caused by an external agent outside the system such as air, water, or magnets. A design for an exoskeleton using external forces has seldom been attempted by researchers. This thesis project focuses on the development of a Limb Gait Simulator based on a Pure External Force and has proven its effectiveness in generating torque on the human leg. The external force is generated through air propulsion using an Electric Ducted Fan (EDF) motor. Such a motor is typically used for remote control airplanes, but their applications can go beyond this. The objective of this research is to generate torque on the human leg through the control of the EDF engines thrust and the opening/closing of the reverse thruster flaps. This device qualifies as "assist as needed"; the user is entirely in control of how much assistance he or she may want. Static thrust values for the EDF engine are recorded using a thrust test stand. The product of the thrust (N) and the distance on the thigh (m) is the resulting torque. With the motor running at maximum RPM, the highest torque value reached was that of 3.93 (Nm). The motor EDF motor is powered by a 6S 5000 mAh LiPo battery. This torque value could be increased with the usage of a second battery connected in series, but this comes at a price. The designed limb gait simulator demonstrates that external forces, such as air, could have potential in the development of future rehabilitation devices.
ContributorsToulouse, Tanguy Nathan (Author) / Sugar, Thomas (Thesis director) / Artemiadis, Panagiotis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The quality of life of many people is lowered by impediments to walking ability caused by neurological conditions such as strokes. Since the ankle joint plays an important role in locomotion, it is a common subject of study in rehabilitation research. Robotic devices such as active ankle-foot orthoses and powered exoskeletons have the potential to be used directly in physical therapy or indirectly in research pursuing more effective rehabilitation methods. This paper presents the LiTREAD, a lightweight three degree-of-freedom robotic exoskeletal ankle device. This novel robotic system is designed to be worn on a user's leg and actuate the foot position during treadmill studies. The robot's sagittal plane actuation is complemented by passive virtual axis systems in the frontal and transverse planes. Together, these degrees of freedom allow the device to approximate the full range of motion of the ankle. The virtual axis mechanisms feature locking configurations that will allow the effect of these degrees of freedom on gait dynamics to be studied. Based on a kinematic analysis of the robot's actuation and geometry, it is expected to meet and exceed its torque and speed targets, respectively. The device will fit either leg of a range of subject sizes, and is expected to weigh just 1.3 kg (2.9 lb.). These features and characteristics are designed to minimize the robot's interference with the natural walking motion. Pending validation studies confirming that all design criteria have been met, the LiTREAD prototype that has been constructed will be utilized in various experiments investigating properties of the ankle such as its mechanical impedance. It is hoped that the LiTREAD will yield valuable data that will expand our knowledge of the ankle and aid in the design of future lower-extremity devices.
ContributorsCook, Andrew James Henry (Author) / Lee, Hyunglae (Thesis director) / Artemiadis, Panagiotis (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
I worked on the human-machine interface to improve human physical capability. This work was done in the Human Oriented Robotics and Control Lab (HORC) towards the creation of an advanced, EMG-controlled exoskeleton. The project was new, and any work on the human- machine interface needs the physical interface itself. So I designed and fabricated a human-robot coupling device with a novel safety feature. The validation testing of this coupling proved very successful, and the device was granted a provisional patent as well as published to facilitate its spread to other human-machine interface applications, where it could be of major benefit. I then employed this coupling in experimentation towards understanding impedance, with the end goal being the creation of an EMG-based impedance exoskeleton control system. I modified a previously established robot-to-human perturbation method for use in my novel, three- dimensional (3D) impedance measurement experiment. Upon execution of this experiment, I was able to successfully characterize passive, static human arm stiffness in 3D, and in doing so validated the aforementioned method. This establishes an important foundation for promising future work on understanding impedance and the creation of the proposed control scheme, thereby furthering the field of human-robot interaction.
ContributorsO'Neill, Gerald D. (Author) / Artemiadis, Panagiotis (Thesis director) / Santello, Marco (Committee member) / Santos, Veronica (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
As robots become more prevalent, the need is growing for efficient yet stable control systems for applications with humans in the loop. As such, it is a challenge for scientists and engineers to develop robust and agile systems that are capable of detecting instability in teleoperated systems. Despite how much research has been done to characterize the spatiotemporal parameters of human arm motions for reaching and gasping, not much has been done to characterize the behavior of human arm motion in response to control errors in a system. The scope of this investigation is to investigate human corrective actions in response to error in an anthropomorphic teleoperated robot limb. Characterizing human corrective actions contributes to the development of control strategies that are capable of mitigating potential instabilities inherent in human-machine control interfaces. Characterization of human corrective actions requires the simulation of a teleoperated anthropomorphic armature and the comparison of a human subject's arm kinematics, in response to error, against the human arm kinematics without error. This was achieved using OpenGL software to simulate a teleoperated robot arm and an NDI motion tracking system to acquire the subject's arm position and orientation. Error was intermittently and programmatically introduced to the virtual robot's joints as the subject attempted to reach for several targets located around the arm. The comparison of error free human arm kinematics to error prone human arm kinematics revealed an addition of a bell shaped velocity peak into the human subject's tangential velocity profile. The size, extent, and location of the additional velocity peak depended on target location and join angle error. Some joint angle and target location combinations do not produce an additional peak but simply maintain the end effector velocity at a low value until the target is reached. Additional joint angle error parameters and degrees of freedom are needed to continue this investigation.
ContributorsBevilacqua, Vincent Frank (Author) / Artemiadis, Panagiotis (Thesis director) / Santello, Marco (Committee member) / Trimble, Steven (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
The focus of this project investigates high mobility robotics by developing a fully integrated framework for a ball-balancing robot. Using Lagrangian mechanics, a model for the robot was derived and used to conduct trade studies on significant system parameters. With a broad understanding of system dynamics, controllers were designed using LQR methodology. A prototype was then built and tested to exhibit desired reference command following and disturbance attenuation.
ContributorsKapron, Mark Andrew (Author) / Rodriguez, Armando (Thesis director) / Artemiadis, Panagiotis (Committee member) / Industrial, Systems & Operations Engineering Prgm (Contributor) / Electrical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05