Exoskeletons

Biomimetic orthosis for the neurorehabilitation of the elbow and shoulder (BONES)

by Julius Klein

Auhors: Klein, J. ; Spencer, S.J. ; Allington, J. ; Minakata, K. ; Wolbrecht, E.T. ; Smith, R. ; Bobrow, J.E. ; Reinkensmeyer, D.J. ;
Univ. of California, Irvine, CA


This paper appears in: Biomedical Robotics and Biomechatronics, 2008. BioRob 2008. 2nd IEEE RAS & EMBS International Conference on
Issue Date : 19-22 Oct. 2008
On page(s): 535 - 541
Print ISBN: 978-1-4244-2882-3
References Cited: 46
INSPEC Accession Number: 10470293
Digital Object Identifier : 10.1109/BIOROB.2008.4762866
Date of Current Version : 27 January 2009

This paper presents a novel design for a 4 degree of freedom pneumatically-actuated upper-limb rehabilitation device.... more This paper presents a novel design for a 4 degree of freedom pneumatically-actuated upper-limb rehabilitation device. BONES is based on a parallel mechanism that actuates the upper arm by means of two passive, sliding rods pivoting with respect to a fixed structural frame. Four, mechanically-grounded pneumatic actuators are placed behind the main structural frame to control shoulder motion via the sliding rods, and a fifth cylinder is located on the structure to control elbow flexion/extension. The device accommodates a wide range of motion of the human arm, while also achieving low inertia and direct-drive force generation capability at the shoulder. A key accomplishment of this design is the ability to generate arm internal/external rotation without any circular bearing element such as a ring, a design feature inspired by the biomechanics of the human forearm. The paper describes the rationale for this device and its main design aspects including its kinematics, range of motion, and force generation capability.

Human-robot synchrony: flexible assistance using adaptive oscillators.

by Tommaso Lenzi

NEUROExos: a variable impedance powered elbow exoskeleton

by Tommaso Lenzi

Sensing Pressure Distribution on a Lower-Limb Exoskeleton Physical Human-Machine Interface

by Tommaso Lenzi

Flexible Assistance using Adaptive Oscillators: Model-based and Model-free Approaches

by Tommaso Lenzi

Measuring human–robot interaction on wearable robots: A distributed approach

by Tommaso Lenzi

Oscillator-based assistance of cyclical movements: model-based and model-free approaches

by Tommaso Lenzi

Ergonomics of exoskeletons: Objective performance metrics

by Mohammad Esmaeili

by: A Schiele, EuroHaptics conference 2009

In this paper it is shown how variation of the kinematic structure of an exoskeleton and variation of its fixation... more In this paper it is shown how variation of the kinematic structure of an exoskeleton and variation of its fixation strength on the human limb influences objective task performance metrics, such as interface load, tracking error and voluntary range of motion in a signal tracking experiment.

An explicit model to predict and interpret constraint force creation in pHRI with exoskeletons

by Mohammad Esmaeili

by: A Schiele, ICRA 2008

It is the goal of this paper to introduce an analytical model that allows predicting and interpreting the... more It is the goal of this paper to introduce an analytical model that allows predicting and interpreting the characteristics of constraint forces generated by misaligned joint axes between human operators and wearable robots during physical human-robot interaction (pHRI). The pHRI model is based on geometric parameters that describe the combined human-robot system. It is applied in this paper to measured constraint forces from a pHRI experiment. The model is validated with the experimental data. The geometrical model parameters are identified from force and position measurements by non-linear parameter optimization. The attachment stiffness and the actual offsets between the exoskeleton and the human joints are estimated. For the tested subject, the stiffness reaches 222 N/m and constraint forces are shown to be in the order of plusmn 10 N. It is shown in this paper how an ergonomically designed wearable robot with passive compensation joints can reduce such interaction forces.

Ergonomic considerations for anthropomorphic wrist exoskeletons: a simulation study on the effects of joint misalignment

by Mohammad Esmaeili

M. Esmaeili, K. Gamage, E. Tan, D. Campolo
IEEE/RSJ International Conference on Intelligent Robots and Systems, San Francisco, 2011.

This work focuses on anthropomorphic exoskeletons for the human wrist. We consider a 2 dof model for the human wrist... more This work focuses on anthropomorphic exoskeletons for the human wrist. We consider a 2 dof model for the human wrist with non intersecting joints and a similar model for the exoskeleton. We assume a viscoelastic attachment between the human hand and the handle of the exoskeleton which on one side allows the different kinematics of the exoskeleton to follow the human wrist and, on the other side, induces reaction forces at all joints, in particular causing discomfort. We relate discomfort to the amount of potential energy stored in the deformation of the viscoelastic attachment.
For a specific exoskeleton implementation, based on kinematic simulations, we report the kinematic mis-match (i.e. differences between the human joints and the corresponding exoskeleton joints) as well as the reaction forces arising when the human joints assume postures throughout their physiological range of motion. Considering the distribution of joint offset (derived from the previous work of other authors) and the asymmetry in the discomfort function (derived from our simulations) we address the ‘one-size-fits-all’ problem and propose an optimal joint offset for the exoskeleton, based on the minimization of the aggregate loss function.