Design and Analysis of Lightweight Lower Limb Exoskeleton for Military Usage

2021 ◽  
Vol 9 (9) ◽  
pp. 896-907
Author(s):  
Sumit Raut
Keyword(s):  
Energy Loss ◽  
Human Body ◽  
Military Personnel ◽  
Lower Limb ◽  
Load Carriage ◽  
Technological Advancement ◽  
Lower Limb Exoskeleton ◽  
Single Person ◽  
Exoskeleton Design ◽  
Great Energy

Abstract: Nowadays, due to technological advancement, weapons are becoming smaller in size, which leads to the number of weapons carried by a single person increasing. As the number of weapons is increasing, then the capacity of the load carriage system of military personnel causes a great energy loss to carry weight. Also, carrying a weight of about 25 kg to 50 kg in different terrain causes different foot injuries which create a strain on the human body. An exoskeleton is a device used to replicate the motion of the human body so that humans can be used to control mechanical power for working on different operations which are beyond human strength. The exoskeleton technology makes it possible to reduce the energy loss of military personnel to produce controlled motion of the exoskeleton in different terrain. Hence, this project is aims to design a lower limb exoskeleton for carrying military load carriage systems. The designing and simulating the lower limb exoskeleton is done on fusion 360. Keywords: lower limb exoskeleton, military exoskeleton, exoskeleton design, exoskeleton analysis

Develop a Flexible Regenerative Exoskeleton to Assist Walking

2018 ◽  
Author(s):  
Longhan Xie ◽  
Xiaodong Li
Keyword(s):  
Kinetic Energy ◽  
Human Body ◽  
Lower Limb ◽  
Metabolic Cost ◽  
Lower Limbs ◽  
Metabolic Energy ◽  
Lower Limb Exoskeleton ◽  
Negative Work ◽  
Lower Limb Muscles ◽  
Assisting Device

During walking, human lower limbs accelerate and decelerate alternately, during which period the human body does positive and negative work, respectively. Muscles provide power to all motions and cost metabolic energy both in accelerating and decelerating the lower limbs. In this work, the lower-limb biomechanics of walking was analyzed and it revealed that if the negative work performed during deceleration can be harnessed using some assisting device to then assist the acceleration movement of the lower limb, the total metabolic cost of the human body during walking can be reduced. A flexible lower-limb exoskeleton was then proposed; it is worn in parallel to the lower limbs to assist human walking without consuming external power. The flexible exoskeleton consists of elastic and damping components that are similar to physiological structure of a human lower limb. When worn on the lower limb, the exoskeleton can partly replace the function of the lower limb muscles and scavenge kinetic energy during lower limb deceleration to assist the acceleration movement. Besides, the generator in the exoskeleton, serving as a damping component, can harvest kinetic energy to produce electricity. A prototype of the flexible exoskeleton was developed, and experiments were carried out to validate the analysis. The experiments showed that the exoskeleton could reduce the metabolic cost by 3.12% at the walking speed of 4.5 km/h.

Lower Limb Exoskeleton Design Based on Knee Joint Assistance

2021 ◽  
Author(s):  
Peng Jiang ◽  
Ye Wang ◽  
Tianqi Shao ◽  
Changsoo Han ◽  
Lin Wang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
Lower Limb Exoskeleton ◽  
Exoskeleton Design

Design and Fabrication of a Low-cost Human Body Lower Limb Exoskeleton

2020 ◽  
Author(s):  
Y. M. Pirjade ◽  
D. R. Londhe ◽  
N. M. Patwardhan ◽  
A. U. Kotkar ◽  
T. P. Shelke ◽  
...  
Keyword(s):  
Human Body ◽  
Lower Limb ◽  
Low Cost ◽  
Lower Limb Exoskeleton

scholarly journals Reducing stiffness of shock-absorbing pylon amplifies prosthesis energy loss and redistributes joint mechanical work during walking

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jenny Anne Maun ◽  
Steven A. Gard ◽  
Matthew J. Major ◽  
Kota Z. Takahashi
Keyword(s):  
Energy Loss ◽  
Lower Limb ◽  
Walking Speed ◽  
Load Carriage ◽  
Mechanical Work ◽  
Transtibial Amputation ◽  
Damping Effect ◽  
Negative Work ◽  
Impact Forces ◽  
Positive Work

Abstract Background A shock-absorbing pylon (SAP) is a modular prosthetic component designed to attenuate impact forces, which unlike traditional pylons that are rigid, can compress to absorb, return, or dissipate energy. Previous studies found that walking with a SAP improved lower-limb prosthesis users’ comfort and residual limb pain. While longitudinal stiffness of a SAP has been shown to affect gait kinematics, kinetics, and work done by the entire lower limb, the energetic contributions from the prosthesis and the intact joints have not been examined. The purpose of this study was to determine the effects of SAP stiffness and walking speed on the mechanical work contributions of the prosthesis (i.e., all components distal to socket), knee, and hip in individuals with a transtibial amputation. Methods Twelve participants with unilateral transtibial amputation walked overground at their customary (1.22 ± 0.18 ms−1) and fast speeds (1.53 ± 0.29 ms−1) under four different levels of SAP stiffness. Power and mechanical work profiles of the leg joints and components distal to the socket were quantified. The effects of SAP stiffness and walking speed on positive and negative work were analyzed using two-factor (stiffness and speed) repeated-measure ANOVAs (α = 0.05). Results Faster walking significantly increased mechanical work from the SAP-integrated prosthesis (p < 0.001). Reducing SAP stiffness increased the magnitude of prosthesis negative work (energy absorption) during early stance (p = 0.045) by as much as 0.027 Jkg−1, without affecting the positive work (energy return) during late stance (p = 0.159), suggesting a damping effect. This energy loss was partially offset by an increase in residual hip positive work (as much as 0.012 Jkg−1) during late stance (p = 0.045). Reducing SAP stiffness also reduced the magnitude of negative work on the contralateral sound limb during early stance by 11–17% (p = 0.001). Conclusions Reducing SAP stiffness and faster walking amplified the prostheses damping effect, which redistributed the mechanical work, both in magnitude and timing, within the residual joints and sound limb. With its capacity to absorb and dissipate energy, future studies are warranted to determine whether SAPs can provide additional user benefit for locomotor tasks that require greater attenuation of impact forces (e.g., load carriage) or energy dissipation (e.g., downhill walking).

scholarly journals Custom-Fit and Lightweight Optimization Design of Exoskeletons Using Parametric Conformal Lattice

2021 ◽  
pp. 129-138
Author(s):  
Fuyuan Liu ◽  
Min Chen ◽  
Lizhe Wang ◽  
Xiang Wang ◽  
Cheng-Hung Lo
Keyword(s):  
Lower Limb ◽  
Optimization Design ◽  
Design Method ◽  
Lightweight Design ◽  
Integrated Design ◽  
Element Analysis ◽  
Lower Limb Exoskeleton ◽  
Structural Framework ◽  
The Finite Element Analysis ◽  
Exoskeleton Design

AbstractThis paper presents an integrated design method for the customization and lightweight design of free-shaped wearable devices, illustrated by a lower limb exoskeleton. The customized design space is derived from the 3D scanning models. Based on the finite element analysis, the structural framework is determined through topology optimization with allowable strength. By means of generative design, the lattice library is constructed to fill the frames under different conformal algorithms. Finally, the proposed method is illustrated by the exoskeleton design case.

scholarly journals Design of a mechanical knee joint for an exoskeleton

2021 ◽  
Vol 338 ◽  
pp. 01003
Author(s):  
Jakub Deda ◽  
Tomasz Mirosław
Keyword(s):  
Knee Joint ◽  
Human Body ◽  
Lower Limb ◽  
Healthy People ◽  
Simple Task ◽  
Lower Limb Exoskeleton ◽  
Mechanical Joints ◽  
Mechanical Equivalent ◽  
Load Carrying ◽  
Body Joints

The main problem of designing a lower limb exoskeleton for healthy people is allowing unconstrained movement along with providing sufficient load carrying capability. It is not a simple task since most of the human body joints have more than one degree of freedom. A designed mechanical equivalent should imitate these movements being outside the human body. Due to this, the mechanical joints must provide shortening or elongation of the structure during load carrying. Authors present biomechanical analyzes of a knee joint and propose a design of a mechanical equivalent of this joint that can be applied in exoskeletons. Additionally, laboratory trials proved suitability of this solution.

scholarly journals Towards Online Estimation of Human Joint Muscular Torque with a Lower Limb Exoskeleton Robot

2018 ◽  
Vol 8 (9) ◽  
pp. 1610 ◽  
Author(s):  
Mantian Li ◽  
Jing Deng ◽  
Fusheng Zha ◽  
Shiyin Qiu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Human Body ◽  
Lower Limb ◽  
Inverse Dynamics ◽  
Estimation Method ◽  
Inverse Dynamic ◽  
Lower Limb Exoskeleton ◽  
Embedded Sensing ◽  
Sensing System ◽  
Exoskeleton Robot ◽  
Wearable Exoskeleton

Exoskeleton robots demonstrate promise in their application in assisting or enhancing human physical capacity. Joint muscular torques (JMT) reflect human effort, which can be applied on an exoskeleton robot to realize an active power-assist function. The estimation of human JMT with a wearable exoskeleton is challenging. This paper proposed a novel human lower limb JMT estimation method based on the inverse dynamics of the human body. The method has two main parts: the inverse dynamic approach (IDA) and the sensing system. We solve the inverse dynamics of each human leg separately to shorten the serial chain and reduce computational complexity, and divide the JMT into the mass-induced one and the foot-contact-force (FCF)-induced one to avoid switching the dynamic equation due to different contact states of the feet. An exoskeleton embedded sensing system is designed to obtain the user’s motion data and FCF required by the IDA by mapping motion information from the exoskeleton to the human body. Compared with the popular electromyography (EMG) and wearable sensor based solutions, electrodes, sensors, and complex wiring on the human body are eliminated to improve wearing convenience. A comparison experiment shows that this method produces close output to a motion analysis system with different subjects in different motion.

Analyzing Motor Primitives of Healthy Subjects Wearing a Lower Limb Exoskeleton

2017 ◽  
Author(s):  
Wilian dos Santos ◽  
Samuel Lourenco ◽  
Adriano Siqueira ◽  
Polyana Ferreira Nunes
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Motor Primitives ◽  
Lower Limb Exoskeleton
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