Design and Characterization of a Lightweight and Fully Portable Remote Actuation System for Use With a Hand Exoskeleton

2016 ◽  
Vol 1 (2) ◽  
pp. 976-983 ◽  
Author(s):  
Christopher J. Nycz ◽  
Tobias Butzer ◽  
Olivier Lambercy ◽  
Jumpei Arata ◽  
Gregory S. Fischer ◽  
...  
2021 ◽  
pp. 103828
Author(s):  
Victor Moreno-SanJuan ◽  
Ana Cisnal ◽  
Juan-Carlos Fraile ◽  
Javier Pérez-Turiel ◽  
Eusebio de-la-Fuente
Keyword(s):  

Aerospace ◽  
2005 ◽  
Author(s):  
Brian Barnes ◽  
Diann Brei ◽  
Jonathan Luntz ◽  
Chris LaVigna

Shape memory alloys are notoriously slow and suffer from creep and controllability issues [1,2]. This paper presents three methods to address these issues: a high-stress cyclic conditioning regime to reduce creep to operationally insignificant levels, an unconventional pulse-width-modulated duty cycle with heatsink to increase frequency to the ten hertz range, and simple position feedback control strategy for motion control. These methods are discussed within the context of a simple antagonistic leveraged SMA actuation system developed for an INertially STAbilized Rifle (INSTAR). An overview of design and basic parameter models for the L-Lever is provided along with benchtop experimental characterization of the quasistatic and dynamic behavior. The actuator was integrated into a one degree of freedom INSTAR platform to demonstrate the insitu methods via barrel control. The methods discussed in this paper led to a fast, low-creep, controllable actuator with outstanding authority resulting in precise barrel control with capabilities to greatly increase shooter accuracy.


2012 ◽  
Vol 17 (5) ◽  
pp. 884-894 ◽  
Author(s):  
Azzurra Chiri ◽  
Nicola Vitiello ◽  
Francesco Giovacchini ◽  
Stefano Roccella ◽  
Fabrizio Vecchi ◽  
...  

Author(s):  
Tomohito HIGUMA ◽  
Taiki YUASA ◽  
Masanori KANAZAWA ◽  
Nobutaka MUKAE ◽  
Makoto HASHIDUME ◽  
...  

2021 ◽  
Vol 7 ◽  
Author(s):  
Jan Dittli ◽  
Urs A. T. Hofmann ◽  
Tobias Bützer ◽  
Gerwin Smit ◽  
Olivier Lambercy ◽  
...  

Wearable robots assist individuals with sensorimotor impairment in daily life, or support industrial workers in physically demanding tasks. In such scenarios, low mass and compact design are crucial factors for device acceptance. Remote actuation systems (RAS) have emerged as a popular approach in wearable robots to reduce perceived weight and increase usability. Different RAS have been presented in the literature to accommodate for a wide range of applications and related design requirements. The push toward use of wearable robotics in out-of-the-lab applications in clinics, home environments, or industry created a shift in requirements for RAS. In this context, high durability, ergonomics, and simple maintenance gain in importance. However, these are only rarely considered and evaluated in research publications, despite being drivers for device abandonment by end-users. In this paper, we summarize existing approaches of RAS for wearable assistive technology in a literature review and compare advantages and disadvantages, focusing on specific evaluation criteria for out-of-the-lab applications to provide guidelines for the selection of RAS. Based on the gained insights, we present the development, optimization, and evaluation of a cable-based RAS for out-of-the-lab applications in a wearable assistive soft hand exoskeleton. The presented RAS features full wearability, high durability, high efficiency, and appealing design while fulfilling ergonomic criteria such as low mass and high wearing comfort. This work aims to support the transfer of RAS for wearable robotics from controlled lab environments to out-of-the-lab applications.


Author(s):  
Matthew Ahlstedt ◽  
Carter Duling ◽  
Yimesker Yihun

Majority of wheelchair users experience upper-body muscular weakness, resulting from neuromuscular diseases, which limit their ability to perform common activities of daily living. A Wheelchair Mounted Robotic Arm (WMRA) will assist these individuals to eat, drink, and move objects as needed. This paper presents the design of a new WMRA as well as the analysis of its function. The design is side-mounted onto either a normal or power wheelchair, and incorporates a slim profile to allow ease of passage through doorways and be otherwise unobtrusive. The arm is easily removable, with assistance, for storage or travel. The mechanical design utilizes a belt and pulley system for remote actuation of each joint, driven by DC Gearmotors located in the base of the arm. This helps to shift the weight closer to the wheelchair and to maintain the required speed, torque and inertia while actively driving each joint of the robot. The end-effector is a unique design, intended to have the adaptability to securely lift a large variety of objects. Grasping simulations were performed on several standard objects which might be encountered daily. Structural, kinematic and workspace analyses are conducted, and results confirm that the designed WMRA is rated to lift a 4 kg payload, while also having a reach of 1.3 meters long radius.


Author(s):  
Adam J. Weall ◽  
James P. Szybist

The characteristics of fuel lean homogeneous charge compression ignition (HCCI) operation using a variety of fuels are well known and have been demonstrated using different engine concepts in the past. In contrast, stoichiometric operation of HCCI is less well documented. Recent studies have highlighted the benefits of operating at a stoichiometric condition in terms of load expansion combined with the applicability of three way catalyst technology to reduce NOx emissions. In this study the characterization of stoichiometric HCCI using gasoline-like fuels was undertaken. The fuels investigated are gasoline, a 50% volume blend of iso-butanol and gasoline (IB50), and an 85% volume blend of ethanol and gasoline (E85). A single cylinder engine operating with direct injection (DI) and spark assist combined with a fully variable hydraulic valve actuation system allowed a wide range of operating parameters to be studied. The resultant fuel properties, which differed in terms of octane rating, fuel oxygenation, and heat of vaporization, show that stoichiometric HCCI is possible using a range of fuels but that these fuel characteristics do have some effect on the combustion characteristics. How these fuel properties can enable an increased engine operating envelope to be achieved, in comparison with both fuel lean HCCI and conventional spark ignited combustion, is then discussed.


2018 ◽  
Vol 3 (3) ◽  
pp. 2101-2108 ◽  
Author(s):  
Urs A. T. Hofmann ◽  
Tobias Butzer ◽  
Olivier Lambercy ◽  
Roger Gassert

Author(s):  
Hamid SadAbadi ◽  
Arvind Chandrasekaran ◽  
Muthukuraman Packirisamy ◽  
Rolf Wuthrich

In order to design the valveless micropump with a Piezo actuator, it is essential to understand the dynamic properties of the actuating system. Besides several other considerations in designing of microfluidic systems, the efficiency of valveless micropumps also strongly depends on parameters of the actuation system including the actuation frequency. Cleary, higher displacement of the diaphragm results in higher output flow rate of the pump. Thus, studying the dynamic behavior of the actuation system forms one of the important considerations for the design of micropumps. Three different models of the actuating system for the fabricated micropump system are proposed with different boundary conditions and are simulated by finite element method using ANSYS. Comparison of the experimental results and the simulation results of the natural frequencies of the system shows that the proposed simulation method can also be now used as a tool to optimize the design of the actuation system in terms of natural frequency of the system.


Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.


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