Design Aspects of Lower Limb Exoskeleton

This research work aimed at the design, simulation, and validation of a lower limb exoskeleton for rehabilitation. The device can provide regressive gait training for patients suffering from lower limb mobility disorders. People suffering from mobility disorders such as spinal cord injuries and other related diseases are of high proportion. Exoskeletons play a vital role in enhancing the lifestyle of people with disorders. Devices that provide locomotion assistance and help in reducing the burden of therapists through effective and repetitive gait training are in high demand. Exoskeletons are further extended to the fields of the military to enhance the performance of physically able persons. Prototype development of lower limb exoskeletons is too expensive People suffering from mobility disorders, such as spinal cord injuries, and other related diseases are in high proportion. Exoskeletons play a vital role in enhancing the lifestyle of people with disorders. Devices that provide locomotion assistance and help in reducing the burden of therapists through effective and repetitive gait training are in high demand. Exoskeletons have further extended to the fields of the military to enhance the performance of physically abled persons. Prototype development of lower limb exoskeletons is too expensive and many of them are patented. The requirement for this system to perform human trials is subjective to several medical and ethical norms. Thus, there exists a need to evaluate and validate the exoskeleton designs. This research work aims at on the design, simulation, and validation of a lower limb exoskeleton for rehabilitation In this work, the design has been made inclusive of different body shapes and sizes. The device has been modeled in SOLIDWORKS and its structural integrity has been analyzed using the ANSYS software. Later, the model has been subjected to environmental assessment and then motion analysis using the ADAMS software. Numerical Simulation The structural integrity analysis has revealed the design to be adequate to carry the applied load as the stresses induced were less than the yield strength of the material. The sustainability analysis showed that LLE made of aluminium alloy had less impact on the environment relative to the other two materials. The structural integrity analysis proves that the proposed design is stable. The sustainability analysis results revealed that, LLE made of aluminium alloy had less impact on the environment compared to the other two materials. The kinematic simulation revealed that, the angular amplitudes, reaction force of right hip and knee joint and contact force between the shoe and ground of the exoskeleton agreed well with experimental findings of literature. The kinematic simulation revealed that the angular amplitudes, the reaction force of the right hip and knee joint, and the contact force between the shoe and the ground of the exoskeleton agreed well with the experimental findings of the literature. A new design approach of lower limb exoskeleton is presented in this work involving structural integrity, sustainability and kinematic simulation of the proposed design. The structural integrity analysis showed that the stresses induced were well below the yield strength and the deformations were negligibly small for the selected three materials. This ensured that the design was adequate enough to carry the applied load safely. Though the stress and deformation of LLE constructed with stainless steel was less in comparison to LLE made up with aluminium and titanium alloys. The weight of LLE made of stainless steel was more by 61.8% and 36.15% relative to aluminium and titanium alloys respectively. The sustainability analysis results revealed that, LLE made of aluminium alloy had less impact on the environment compared to the other two materials. Hence, if environmental impact is top priority, aluminium alloy is the suitable material for the LLE design. The kinematic simulation revealed that, the angular amplitudes, reaction force of right hip and knee joint and contact force between the shoe and ground of the exoskeleton agreed well with experimental findings of literature. The angular changes of right hip and knee joints are smooth ensuring no injury to the wearer. Not applicable