Development of a Novel Shoulder Exoskeleton Using Parallel Actuation and Slip

2016 ◽  
Author(s):  
Justin Hunt ◽  
Panagiotis Artemiadis ◽  
Hyunglae Lee
Keyword(s):  
Glenohumeral Joint ◽  
Translational Motion ◽  
Parallel Architecture ◽  
Slip Model ◽  
Slip Mechanism ◽  
Novel Technologies ◽  
Mechanical Interference ◽  
Stiffness Characteristics ◽  
Spherical Parallel Manipulator ◽  
Kinematic Solution

This paper presents a 5 degree-of-freedom (DoF) low inertia shoulder exoskeleton that was developed using two novel technologies with a broad range of application. The first novelty is a 3-DoF spherical parallel manipulator (SPM) that uses three linear actuators. Each actuator is designed using a method of motion coupling such that the pitch and linear stroke DoF are dependent. By using an SPM, this shoulder exoskeleton takes advantage of the inherent low effective inertia property of parallel architecture. The second novelty is a 2-DoF passive slip mechanism that couples the user’s upper arm to the SPM. This slip mechanism increases system mobility and prevents joint misalignment caused by the translational motion of the user’s glenohumeral joint from introducing mechanical interference that could affect the device’s kinematic solution or harm the user. An experiment to validate the kinematics of the SPM was performed using motion capture. A computational slip model was created to quantify the slip mechanism’s response for different conditions of joint misalignment. In addition to offering a low inertia solution for the rehabilitation or augmentation of the human shoulder, the presented device demonstrates the technologies of actuator motion coupling and passive slip for use in exoskeletal systems. The use of motion coupling could be applied to other types of parallel actuated architectures in order to constrain the kinematics or improve stiffness characteristics. Passive slip mechanisms could have application in either serial or parallel actuated systems as a means of negating the adverse effects of joint misalignment.

A Novel Shoulder Exoskeleton Robot Using Parallel Actuation and a Passive Slip Interface

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Justin Hunt ◽  
Hyunglae Lee ◽  
Panagiotis Artemiadis
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Glenohumeral Joint ◽  
Translational Motion ◽  
Euler Angle ◽  
Inverse Kinematic ◽  
New Method ◽  
Novel Technologies ◽  
Manipulator Design ◽  
Spherical Parallel Manipulator

This paper presents a five degrees-of-freedom (DoF) low inertia shoulder exoskeleton. This device is comprised of two novel technologies. The first is 3DoF spherical parallel manipulator (SPM), which was developed using a new method of parallel manipulator design. This method involves mechanically coupling certain DoF of each independently actuated linkage of the parallel manipulator in order to constrain the kinematics of the entire system. The second is a 2DoF passive slip interface used to couple the user upper arm to the SPM. This slip interface increases system mobility and prevents joint misalignment caused by the translational motion of the user's glenohumeral joint from introducing mechanical interference. An experiment to validate the kinematics of the SPM was performed using motion capture. The results of this experiment validated the SPM's forward and inverse kinematic solutions through an Euler angle comparison of the actual and command orientations. A computational slip model was created to quantify the passive slip interface response for different conditions of joint misalignment. In addition to offering a low inertia solution for the rehabilitation or augmentation of the human shoulder, this device demonstrates a new method of motion coupling, which can be used to impose kinematic constraints on a wide variety of parallel architectures. Furthermore, the presented device demonstrates a passive slip interface that can be used with either parallel or serial robotic systems.

On the kinematics of the 3-RRUR spherical parallel manipulator

Robotica ◽  
2009 ◽  
Vol 28 (6) ◽  
pp. 821-832 ◽  
Author(s):  
R. Deidda ◽  
A. Mariani ◽  
M. Ruggiu
Keyword(s):  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Mobility Analysis ◽  
Geometrical Condition ◽  
Mechanical Interference ◽  
Fixed Base ◽  
Spherical Wrist ◽  
Moving Platform ◽  
Three Degree Of Freedom ◽  
Spherical Parallel Manipulator

SUMMARYIn the present paper, the kinematics of a three-degree-of-freedom spherical wrist is investigated. The wrist consists of a fixed base connected to a moving platform by three identical legs, each with a RRUR chain (R and U denote a revolute pair and a universal pair, respectively). For each leg, the first R pair is to be considered actuated. Although in previous works the kinematics synthesis of this architecture was carried out, no detailed studies were presented on the kinematic issues of the wrist. This paper presents the mobility analysis, the direct and inverse position kinematics, the differential kinematics of the manipulator including inspection on the jacobian matrix and the analysis of the singularities. The geometrical condition matched in case of mechanical interference between legs is addressed, too. A numerical example of the manipulator kinematics was performed to obtain the workspace, the condition number and the mechanical inteference condition.

scholarly journals Recurrence Time Analysis of the 1883 (Mw 8.6 ~ 9.1) Paleo Megathrust Earthquake in West Bengkulu, Sumatra, Indonesia, Using Plate Kinematic Model for Supporting Mitigation Program

2020 ◽  
Author(s):  
Jaya Murjaya ◽  
Dwikorita Karnawati ◽  
Subagyo Pramumijoyo ◽  
Supriyanto Supriyanto ◽  
Rahmat Setyo Yuliatmoko ◽  
...  
Keyword(s):  
Scaling Law ◽  
Kinematic Model ◽  
Slip Rate ◽  
Recurrence Time ◽  
Slip Model ◽  
Time Analysis ◽  
Megathrust Earthquake ◽  
Slip Mechanism ◽  
Rigidity Modulus

Abstract The great paleo-megathrust earthquake occurred in west Bengkulu-Sumatra on November 25, 1833 and it was estimated to have the magnitude of about Mw 8.6–9.1. This earthquake triggered a tsunami that has 3-4 m height in the Bengkulu coastal and its vicinity. The fundamental earthquake parameter was not known exactly, thus it was difficult to conduct the analysis. We tried to analyze it using scaling law relations of earthquake parameter and magnitude scenarios to estimate the recurrence time based on the plate kinematic model to support the long-term mitigation program. The recurrence time was estimated at 179 years, 250 years, and 314 years if the earthquake is assumed to have a dip-slip mechanism, plate slip rate about 7 cm/year, and magnitude scenarios of 8.6, 8.8, and 9.1 respectively. Then, the recurrence time was estimated at 314 years, 438 years, and 550 years respectively if the earthquake is assumed to have a plate slip rate about 4 cm/year. The other estimation was used the strain rate value of about 1.19 x 10-14/s for Sumatra region and the rigidity modulus of 3.1011 dyne/cm2. We found the recurrence estimation of about 161 years (Mw 8.6), 222 years (Mw 8.8), and 220 years (Mw 9.1) for the dip-slip model. Meanwhile, if this study used all rupture models, the recurrence time of the Bengkulu paleo megathrust earthquake would be about 370 years (Mw 8.6), 558 years (Mw 8.8), and 553 years (Mw 9.1).

Automated Border Control: Criminalizing the “Hidden Intent” of Migrant Embodiment

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Felicity Amaya Schaeffer
Keyword(s):  
Homeland Security ◽  
Racial Bias ◽  
Great Part ◽  
The Body ◽  
Industrial Complex ◽  
Border Control ◽  
Computer Engineering ◽  
Novel Technologies ◽  
Surveillance Technology ◽  
Border Zones

I argue that we are entering an automated era of border control that I label a border-biosecurity industrial complex. Funded in great part by the Department of Homeland Security (DHS), scientific research and automated surveillance technologies promise the state innovative and supposedly unbiased solutions to the challenge of border control and security. This article spotlights a border surveillance technology called AVATAR (Automated Virtual Agent for Truth Assessment in Real-Time). Analyzing this technology, which was funded by the DHS and developed by faculty at the University of Arizona’s National Center for Border Security and Immigration (BORDERS), allows me to assess how the emphasis on novel technologies to detect terrorists unleashes the search for ubiquitous surveillance devices programmed to detect deviant behavioral and physiological movements. I offer a wider view of this technology-in-the-making by analyzing how university research in aerial defense, the psychology of deception, the life sciences, and computer engineering influences the development of surveillance devices and techniques. I explore how, during a posthuman era, automated technologies detect and racialize “suspect life” under the guise of scientific neutrality and supposedly free from human interference. Suspect life refers to the racial bias preprogrammed into algorithms that compute danger or risk into certain human movements and regions such as border zones. As these technologies turn the body into matter, they present biological life as a more scientifically verifiable truth than human verbal testimony, moving border control from the adjudication of law through the subjective interview to the automated body that speaks a truth more powerful than a complex story can tell.

The Recent Revolution in High Performance Computing

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 5-6
Author(s):  
Horst D. Simon
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
New Technologies ◽  
New Technology ◽  
Parallel Architecture ◽  
Time Frame ◽  
Good News ◽  
Computing Industry ◽  
Time And Energy ◽  
Performance Computing

Recent events in the high-performance computing industry have concerned scientists and the general public regarding a crisis or a lack of leadership in the field. That concern is understandable considering the industry's history from 1993 to 1996. Cray Research, the historic leader in supercomputing technology, was unable to survive financially as an independent company and was acquired by Silicon Graphics. Two ambitious new companies that introduced new technologies in the late 1980s and early 1990s—Thinking Machines and Kendall Square Research—were commercial failures and went out of business. And Intel, which introduced its Paragon supercomputer in 1994, discontinued production only two years later.During the same time frame, scientists who had finished the laborious task of writing scientific codes to run on vector parallel supercomputers learned that those codes would have to be rewritten if they were to run on the next-generation, highly parallel architecture. Scientists who are not yet involved in high-performance computing are understandably hesitant about committing their time and energy to such an apparently unstable enterprise.However, beneath the commercial chaos of the last several years, a technological revolution has been occurring. The good news is that the revolution is over, leading to five to ten years of predictable stability, steady improvements in system performance, and increased productivity for scientific applications. It is time for scientists who were sitting on the fence to jump in and reap the benefits of the new technology.

Dynamic Damping and Stiffness Characteristics of the Rolling Tire

2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin
Keyword(s):  
Dynamic Behavior ◽  
Variable Parameter ◽  
Low Frequency ◽  
Vertical Load ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Vehicle Simulation ◽  
Dynamic Damping ◽  
Speed Range ◽  
Stiffness Characteristics

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.

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