Preliminary design and development of a low-cost lower-limb exoskeleton system for paediatric rehabilitation

2021 ◽  
pp. 095441192199494
Author(s):  
Jyotindra Narayan ◽  
Santosha Kumar Dwivedy
Keyword(s):  
Dynamic Analysis ◽  
Lower Limb ◽  
Low Cost ◽  
Coupled System ◽  
Contact Forces ◽  
Lagrange Principle ◽  
Element Analysis ◽  
Lower Limb Exoskeleton ◽  
Simulation Results ◽  
Paediatric Rehabilitation

In this work, the design, modeling, and development of a low-cost lower limb exoskeleton (LLES) system are presented for paediatric rehabilitation (age: 8–12 years, mass: 25–40 kg, height: 115–125 cm). The exoskeleton system, having three degrees-of-freedom (DOFs) for each limb, is designed in the SolidWorks software. A wheel support module is introduced in the design to ensure the user’s stability and safety. The finite element analysis of the hip joint connector along with the wheel support module is realized for maximum loading conditions. The holding torque capacity of exoskeleton joints is estimated using an affordable spring-based experimental setup. A working prototype of the LLES is developed with holding torque rated actuators. Thereafter, the dynamic analysis for the human-exoskeleton coupled system is carried out using the Euler-Lagrange principle and SimMechanics model. The simulation results of estimating joint actuator torques are obtained for two paraplegic subjects (Case I: 10 years age, 30 kg mass, 120 cm height and Case II: 12 years age, 40 kg mass, 125 cm height). The details of input parameters such as body mass, link lengths, joint angles, and contact forces are discussed. The simulation results of dynamic analysis have shown the potential of estimating the torques of joint actuators for the developed prototype during motion assistance and gait rehabilitation.

Numerical Analysis of the Dynamic Interaction Between Pantograph and Overhead Contact Line Using FEM

2011 ◽  
Author(s):  
Sung Pil Jung ◽  
Tae Won Park ◽  
Jin Hee Lee
Keyword(s):  
Numerical Analysis ◽  
Contact Line ◽  
Dynamic Interaction ◽  
Fe Analysis ◽  
Contact Forces ◽  
Analysis Program ◽  
Analysis Model ◽  
Element Analysis ◽  
Simulation Results ◽  
Analysis Models

This study aims to create a numerical analysis model which can investigate the interaction between pantograph and overhead contact line used for railway vehicles, and validate the simulation results according to EN 50318 standards. Finite element analysis models of pantograph and overhead contact line are created using SAMCEF, a commercial FE analysis program, and mean, standard deviation, maximum and minimum values of contact forces are obtained. The simulation results are validated according to EN 50318, and the reliability of SAMCEF as an analysis solver of railway vehicle’s catenary system is discussed.

A Study on Effects of Gear Backlash on Differential Vibration

2014 ◽  
Vol 945-949 ◽  
pp. 730-734
Author(s):  
Jin Li Xu ◽  
Peng Wei ◽  
Feng Yun Huang ◽  
Hong Jun Wang
Keyword(s):  
Dynamic Analysis ◽  
Mechanical System ◽  
Dynamic Simulation ◽  
3D Model ◽  
Contact Forces ◽  
Planetary Gears ◽  
Time Dynamic ◽  
Gear Backlash ◽  
Impact Theory ◽  
Simulation Results

Based on UG and Automatic Dynamic Analysis of Mechanical System (ADAMS), the 3D model of differential was constructed and the real-time dynamic simulation of differential was achieved. The effects of gear backlash between half axle gears and planetary gears on the vibration of differential are studied. To increase the credibility of simulation results , the contact forces between half axle gears and planetary gears were calculated based on the Hertz elasticity impact theory.

Design and Analysis of a Lower Limb Exo-Skeleton Suit for Post Stroke Patient: Static and Ergonomic Analyses

Mekatronika ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 6-18
Author(s):  
S. A. F. Suhaimi ◽  
N. M. H. T. Suhaimi ◽  
M. H. M Ramli
Keyword(s):  
Lower Limb ◽  
Computer Aided Design ◽  
Equivalent Stress ◽  
Evaluation Process ◽  
Design Matrix ◽  
Stroke Patients ◽  
Element Analysis ◽  
Average Mass ◽  
Post Stroke ◽  
Lower Limb Exoskeleton

This paper presents a study on the development of a lower limb exoskeleton suit (exo-suit) for post-stroke patients. The exo-suit is designed and developed for restoration of post-stroke patients' gait motion (ability to use their lower limb joints) and analysis on ergonomics and statics are also considered. The mechanical structure of the exo-suit is proposed according to the anatomy of Asian people with an average mass of eighty kilograms in order that it is fitted perfectly. The conceptual design is established and selected by a dedicated design matrix and compared using the matrix evaluation process, and then Computer-Aided Design (CAD) software CATIA is used to create the 3D model. The design has undergone an evaluation of static structural and ergonomic analysis via CATIA and ANSYS Finite Element Analysis (FEA) software. Two materials are used in the static structural analysis, one is aluminium alloy, the other is steel material. The result of equivalent stress for both materials is within the allowable range of 29.511MPa to 1168.4 MPa. For RULA (Rapid Upper Limb Assessment) Analysis, the results showed that all three postures (static, intermittent, and repeated) yield acceptable final score which is 1 for intermittent and 2 for static and repeated postures.  

Dynamic Analysis of Lower Limb Exoskeleton Motion and Control Using Differential Transform Method

2021 ◽  
Vol 51 ◽  
pp. 77-94
Author(s):  
Olurotimi A. Adeleye ◽  
Tamunomiete S. Ekine ◽  
Ahmed A. Yinusa
Keyword(s):  
Dynamic Analysis ◽  
Lower Limb ◽  
Nonlinear Dynamic ◽  
Differential Transform Method ◽  
Transform Method ◽  
Positive Direction ◽  
Lower Limb Exoskeleton ◽  
Applied Torque ◽  
Differential Transform ◽  
And Control

In this study, the nonlinear dynamic analysis of the motion and control of the lower limb exoskeleton using differential transform method is presented. Devices for medical processes are continuously undergoing improvement such as enhancing and assisting automatic therapies with flexible and configurable programs for treating people with partial disability in lower limbs as applied in lower-limb exoskeleton. The configurable programs in this exoskeleton can be applied to observe and control the motion of the exoskeleton for effective physiotherapy and reduced rehabilitation time for patients with such disability. Hence, a two degree of freedom nonlinear dynamic model for the motion and control of the lower limb exoskeletons was developed for two links. The nonlinear dynamic models are solved by applying the differential transform method (DTM) and verified with the forth order Runge-Kutta numerical method (RK4). The effects of the applied torque on the two links are investigated and it is observed that Link 1 has large negative deflection amplitude that drives link 2 towards the opposite positive direction. An increase in the applied torque resulted in increase in the amplitude of the system for all initial condition considered. This in turns increases the nonlinear dynamic behavior of link 2 due to its lower mass value. The speed of both links dampens out over the history due to the presence of damping term. At equilibrium, both links are in phase and have the same amplitude over the time history. This study provides an analytical tool for observing and controlling the motions of the lower limb exoskeleton and for improving the designs of the medical device.

scholarly journals Low Cost Lower Limb Exoskeleton for Assisting Gait Rehabilitation

2019 ◽  
Author(s):  
Luis I. Minchala ◽  
Anthony J. Velasco ◽  
Jonathan M. Blandin ◽  
Fabian Astudillo-Salinas ◽  
Andres Vazquez-Rodas
Keyword(s):  
Lower Limb ◽  
Low Cost ◽  
Gait Rehabilitation ◽  
Lower Limb Exoskeleton

scholarly journals Design of Lower Limb Exoskeleton using Gearbox for Rehabilitation of Paralyzed Patients

2020 ◽  
Vol 9 (5) ◽  
pp. 112-115
Keyword(s):  
Dynamic Analysis ◽  
Lower Limb ◽  
Mechanical Design ◽  
Design Procedure ◽  
Primary Analysis ◽  
Static And Dynamic Analysis ◽  
Lower Limb Exoskeleton ◽  
Standard Design ◽  
Cord Injury ◽  
Paralyzed Patient

The number of people with mobility disorder cause by stroke spinal cord injury or related disease is increasing rapidly.To improve quality of life of this people device that can assist them to regain the ability to work are of great demand. Robotic devices are generally used for purpose.The aim of this paper is to present the design and analysis of lower limb exoskeletons.The Exoskeleton is designed by Mechanical Design Procedure for linkages and against the Position values obtained from Gait Analysis.The Gearbox is designed using standard design procedure. This exoskeleton work on the principle of robotics by using sensors, actuator like DC motor. Gait analysis is used as a primary analysis followed by static and dynamic analysis of designed model.Static and Dynamic Analysis is performed in ANSYS Workbench. This exoskeleton will be used for paralyzed patient (paraplegia)as well as for the people who have had accidents for lower body.The limitation of this work is the same exoskeleton cannot be used for all person and a small defect in sensor and other electronic devices will stop the exoskeleton. Using this exoskeleton a paralyzed patient will be able to rehabilitate they will be able to perform stand to sit motion.

Static-dynamic analysis of a lower limb exoskeleton controlled by a fuzzy PD

2017 ◽  
Author(s):  
Luis Calle Arevalo ◽  
Paul Chacon Jaramillo ◽  
Marco Amaya Pinos ◽  
Julio Zambrano Abad ◽  
Rene Avila Campoverde
Keyword(s):  
Dynamic Analysis ◽  
Lower Limb ◽  
Lower Limb Exoskeleton ◽  
Fuzzy Pd
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