Design of a multi-resiliency exoskeleton and its physiologic cost evaluation in uphill walking and stair climbing locomotion

2021 ◽  
pp. 095440622110263
Author(s):  
Enguo Cao ◽  
MengYi Ren ◽  
YuTian Cui ◽  
Kun Wang ◽  
Bin Yang
Keyword(s):  
Inverse Dynamics ◽  
Human Locomotion ◽  
Cost Evaluation ◽  
Stair Climbing ◽  
Design Parameters ◽  
Total Consumption ◽  
Lower Limb Exoskeleton ◽  
Series Of Experiments ◽  
Inverse Dynamics Analysis ◽  
Uphill Walking

Background In recent years, as the large own weight of active exoskeleton brings some difficulty to energy-sustainable, studies have shown that passive lower extremity exoskeletons can also reduce the energy consumption of human locomotion, but the energy saving is still relatively small compared with the total consumption. Methods A passive lower limb exoskeleton named Multi-Resiliency was described, and design parameters were estimated based on inverse dynamics. Furthermore, a series of experiments was designed for assessing the assisting effect of the exoskeleton in uphill walking and upstairs activities. Results In the inverse dynamics analysis, the spring release angle θmax was confirmed to be 45° for increasing assist performance of the exoskeleton. In the exoskeleton wearing experiments, the energy expenditure of subjects were decreased by 14.3% in uphill walking test and 16.0% in stair climbing test respectively. Conclusion The results show that the design of Multi-Resiliency exoskeleton is reasonable and it may effectively improve walking efficiency during uphill walking and stair climbing activities.

A Lower Limb Exoskeleton Recycling Energy From Knee and Ankle Joints to Assist Push-Off

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Yihua Chang ◽  
Weixin Wang ◽  
Chenglong Fu
Keyword(s):  
Knee Joint ◽  
Ankle Joint ◽  
Lower Limb ◽  
Stance Phase ◽  
Inverse Dynamics ◽  
Preliminary Evaluation ◽  
Positive Power ◽  
Storage Element ◽  
Lower Limb Exoskeleton ◽  
Inverse Dynamics Analysis

Abstract This paper presents the design and preliminary evaluation of a quasi-passive lower limb exoskeleton for walking efficiency improvements. The exoskeleton recycles the negative work performed by the knee joint in late swing phase and the ankle joint in mid-stance phase, to assist ankle push-off in late-stance phase when a burst of positive power is needed. The exoskeleton consists of a torsion spring as an energy storage element, and two clutches attached to both ends of the spring to control the timing of recycling and releasing energy in a gait cycle. The two clutches are actively controlled by two small servo motors with very low power consumption based on the plantar pressure. The novelty of this exoskeleton is it makes the extra kinetic energy dissipated at the knee joint reusable, by transferring it to the ankle joint to assist positive power generation during push-off, for the first time. Eight male subjects walked with the exoskeleton engaged (EXO_ON), disengaged (EXO_OFF), and without the exoskeleton (NO_EXO). Inverse dynamics analysis demonstrated reduced negative biological work at the knee joint during late swing and at the ankle joint during mid stance, as well as reduced positive biological work at the ankle joint during late stance comparing the EXO_ON to EXO_OFF conditions. These results prove the effectiveness of the exoskeleton at joint level.

scholarly journals Evaluation of Operability for a Competition Wheelchair Using Manipulability

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 53
Author(s):  
Kazuki Taira ◽  
Yuki Kobayashi ◽  
Katsumasa Tanaka
Keyword(s):  
Energy Efficiency ◽  
Inverse Dynamics ◽  
Reaction Force ◽  
Design Parameters ◽  
Dynamics Analysis ◽  
Upper Limbs ◽  
Linear Operation ◽  
Biomechanical Parameters ◽  
Hand Force ◽  
Inverse Dynamics Analysis

The objective of this study was to evaluate the operability for a competition wheelchair by estimating biomechanical parameters during the forward linear operation of a wheelchair using an inverse dynamics analysis. During operation of the wheelchair, the vector of ideal hand force in the posture of the arm was calculated using the reaction force between the hand and the wheel. Hand manipulability was defined as the angles between its vector and the vector of hand force estimated from the simulation. The effects of the design parameters for the wheelchair on manipulability were investigated by conducting simulations with changes in axle positions. As a result, it may be effective to set the axle to higher positions to increase the energy efficiency of the upper limbs during operation of the wheelchair. This indicates that adjustment of the axle position leads to improvement of operability of the wheelchair.

scholarly journals Design, Analysis, and Experiment on a Novel Stick-Slip Piezoelectric Actuator with a Lever Mechanism

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 863 ◽  
Author(s):  
Weiqing Huang ◽  
Mengxin Sun
Keyword(s):  
Piezoelectric Actuator ◽  
Simple Structure ◽  
Fast Response ◽  
Displacement Sensor ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Stick Slip ◽  
Lever Mechanism ◽  
Series Of Experiments ◽  
Stator Design

A piezoelectric actuator using a lever mechanism is designed, fabricated, and tested with the aim of accomplishing long-travel precision linear driving based on the stick-slip principle. The proposed actuator mainly consists of a stator, an adjustment mechanism, a preload mechanism, a base, and a linear guide. The stator design, comprising a piezoelectric stack and a lever mechanism with a long hinge used to increase the displacement of the driving foot, is described. A simplified model of the stator is created. Its design parameters are determined by an analytical model and confirmed using the finite element method. In a series of experiments, a laser displacement sensor is employed to measure the displacement responses of the actuator under the application of different driving signals. The experiment results demonstrate that the velocity of the actuator rises from 0.05 mm/s to 1.8 mm/s with the frequency increasing from 30 Hz to 150 Hz and the voltage increasing from 30 V to 150 V. It is shown that the minimum step distance of the actuator is 0.875 μm. The proposed actuator features large stroke, a simple structure, fast response, and high resolution.

ANALYSIS OF THE EFFECTS OF SPINE STABILIZATION EXERCISES USING A WHOLE BODY TILT DEVICE ON MUSCLE FORCES IN THE SPINE

2014 ◽  
Vol 14 (06) ◽  
pp. 1440003
Author(s):  
KAP-SOO HAN ◽  
CHANG HO YU ◽  
MYOUNG-HWAN KO ◽  
TAE KYU KWON
Keyword(s):  
Inverse Dynamics ◽  
The Elderly ◽  
Body Tilt ◽  
Whole Body ◽  
Muscle Forces ◽  
Activation Patterns ◽  
Muscle Strengthening ◽  
Spine Stabilization ◽  
Inverse Dynamics Analysis ◽  
The Right

The objective of the study was to investigate the effects of 3D stabilization exercises using a whole body tilt device on forces in the trunk, such as individual muscle forces and activation patterns, maximum muscle activities and spine loads. For this sake, a musculoskeletal (MS) model of the whole body was developed, and an inverse dynamics analysis was performed to predict the forces on the spine. An EMG measurement experiment was conducted to validate the muscle forces and activation patterns. The MS model was rotated and tilted in eight different directions: anterior (A), posterior (P), anterior right (AR), posterior right (PR), anterior left (AL), posterior left (PL), right (R) and left (L), replicating the directions of the 3D spine balance exercise device, as performed in the experiment. The anterior directions of the tilt primarily induced the activation of long and superficial back muscles and the posterior directions activated the front muscles. However, deep muscles, such as short muscles and multifidi, were activated in all directions of the tilt. The resultant joint forces in the right and left directions of the tilt were the least among the directions, but higher muscle activations and more diverse muscle recruitments than other positions were observed. Therefore, these directions of tilt may be suitable for the elderly and rehabilitation patients who require muscle strengthening with less spinal loads. In the present investigation, it was shown that 3D stabilization exercises could provide considerable muscle exercise effects with a minimum perturbation of structure. The results of this study can be used to provide safety guidelines for muscle exercises using this type of tilting device. Therefore, the proposed direction of tilt can be used to strengthen targeted muscles, depending on the patients' muscular condition.

Design and fabrication of a lower limb exoskeleton to assist in stair ascending

2019 ◽  
Vol 46 (2) ◽  
pp. 290-299 ◽  
Author(s):  
Payman Joudzadeh ◽  
Alireza Hadi ◽  
Bahram Tarvirdizadeh ◽  
Danial Borooghani ◽  
Khalil Alipour
Keyword(s):  
Lower Limb ◽  
System Performance ◽  
Design Methodology ◽  
Stair Climbing ◽  
Robot Design ◽  
Disabled People ◽  
Content Type ◽  
Lower Limb Exoskeleton ◽  
Knee Braces ◽  
Novel Design

Purpose This paper aims to deal with the development of a novel lower limb exoskeleton to assist disabled people in stair ascending. Design/methodology/approach For this purpose, a novel design of a mixture of motors and cables has been proposed for users to wear them easily and show the application of the system in stair climbing. Findings One of the prominences of this study is the provided robot design where four joints are actuated with only two motors; each motor actuates either the knees or ankles. Another advantage of the designed system is that with motors placed in a backpack, the knee braces can be worn under clothes to be concealed. Finally, the system performance is evaluated using electromyography (EMG) signals showing 28 per cent reduction in energy consumption of related muscles. Originality/value This investigation deals with the development of a novel lower limb exoskeleton to assist disabled people in stair ascending.

scholarly journals Control of the lighting system using a genetic algorithm

2012 ◽  
Vol 16 (suppl. 1) ◽  
pp. 237-250 ◽  
Author(s):  
Velimir Congradac ◽  
Bosko Milosavljevic ◽  
Jovan Velickovic ◽  
Bogdan Prebiracevic
Keyword(s):  
Genetic Algorithm ◽  
Social Life ◽  
Electricity Consumption ◽  
Energetic Efficiency ◽  
Lighting System ◽  
Total Consumption ◽  
The Social ◽  
Series Of Experiments ◽  
The Mathematical Model ◽  
Very High

The manufacturing, distribution and use of electricity are of fundamental importance for the social life and they have the biggest influence on the environment associated with any human activity. The energy needed for building lighting makes up 20-40% of the total consumption. This paper displays the development of the mathematical model and genetic algorithm for the control of dimmable lighting on problems of regulating the level of internal lighting and increase of energetic efficiency using daylight. A series of experiments using the optimization algorithm on the realized model confirmed very high savings in electricity consumption.

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