Comparative analysis of exoskeletal actuators (original) (raw)

A Review Study on the Design of an Exoskeleton Robot

2021

Exoskeleton devices have a wide range of therapeutic and assistive utilities in life and they can provide essential support for limb movements with increased strength and endurance. This paper is presented to review the development of different approaches in controller design, actuation method, and transmission for exoskeletons. Here, the coupled nonlinear dynamics of the user and exoskeleton are a significant factor in developing and realizing effective control algorithms. So, after a short review of dynamic modeling of an exoskeleton, the application of some common controllers is provided. Also, due to the direct interaction of the user's body, it is necessary to utilize appropriate and convenient hardware components. In addition, a suitable combination of actuator and transmission systems can noticeably improve the performance, precision, and functionality of the robot. This review is represented to aid researchers in the fields of robotic therapy and exoskeleton devices in a...

A Study on the State of Powered-Exoskeleton Design for Lower Extremities

In this paper, previous studies in powered exoskeleton and their contributions in the field of robotics technology are presented, together with their corresponding control system. Specific problems and issues that were encountered and the solutions made to resolve the problems will be discussed. Gait cycle analysis and human body dynamic model will also be covered in the study to understand the biomechanics and the dynamics behind human walking

A Survey in the Different Designs and Control Systems of Powered Exoskeleton for Lower Extremities

Journal of Mechanical Engineering and Biomechanics, 2017

In this paper, previous studies in powered exoskeleton and their contributions in the field of robotics technology are presented, together with their corresponding control system. Specific problems and issues that were encountered and the solutions made to resolve the problems will be discussed. Gait cycle analysis and human body dynamic model will also be covered in the study to understand the biomechanics and the dynamics behind human walking.

Design of a Lower Limb Exoskeleton

Robotic lower limb exoskeletons have been built for augmenting human performance, assisting people with disabilities, studying human physiology, and retraining motor deficiencies. The main function of a powered exoskeleton is to assist the wearer by boosting their strength and endurance. Our project aims to develop an ergonomic, cost effective, yet powerful exoskeleton to aid the disabled and soldiers. We plan to use a light weight, but stiff material capable enough to handle the compressive stresses developed by the weight of the user. The links are driven using independent motors. Electric motors are used for the actuators due to their higher efficiency and lower weight. The system is fastened to the wearer using broad Velcro strips to employ universal compatibility and to avoid discomfort. The current system uses a pre-programmed microcontroller to actuate the motors. The speed and number of revolutions are determined in accordance with the human gait cycle. In order to obtain the required motion, sprockets are used along with simple cable-pulley system, thereby decreasing the overall weight of the system. The pace can be altered by suitably changing the voltage supplied to the motors using the driver circuit. The primary benefactors of the product will be the senior citizen, whose numbers are expected to shoot up to 70 percentages by 2050. So an ergonomic and cost effective exoskeletons market is expected to go nowhere but upwards. The links of our product are so designed to be 95 percentile human, so that it fits practically everyone. Provisions for small adjustments are also provided for additional comfort. The compact and vertical design not only creates an aesthetic appearance. It is also commendable that the existing technological exoskeletons rest a fortune and hence has not achieved a great appeal in the market. It is in this context that our cost effective exoskeleton becomes commercially important.

ROBOTIC EXOSKELETONS: A REVIEW ON DEVELOPMENT

Transstellar Journals, 2019

Robotic exoskeletons are one of the extremely vigorous zones in recent robotic exploration as it is an emerging product which fulfils different applications in society. In the last six decades, many research works have been carried out to escalate the staging of exoskeletons thus flourish them to nearly mercenary products. This paper briefly studious the current progress of the robotic exoskeleton structures and furnishes awareness into the modern evolution in robotic exoskeletons along with their requisitions and also provides detailed information regarding required parameters to be concentrated for designing and fabrication of the robotic exoskeleton. In the brief appraisal it is attentive to classify the concise history, need, classification, applications, confronts facing by them, design considerations and technology required to understand and design, Software's used for designing and simulation of the exoskeletons. Further, some concluding remarks are perceived which could be useful for ensuing work.

Past, Present and Future of Assistive Robotic Lower Limb Exoskeletons

MATEC Web of Conferences

Many research teams have developed various innovations in the field of assistive robotic exoskeletons for human lower limbs. Especially in the recent years, because of the expeditious technological development, much work has been done and published in the scientific communities. However, in the publications, for different reasons and constraints, the information available is in bits and pieces. Most papers only could manage to speak of the individual aspects like the mechanical design or state machine or interface or another control scenario, etc. This is why an attempt of bringing scientific aspects together is done in this work. This is achieved by considering the most popular and various kinds of exoskeletons. Therefore, in this chapter an overview on the aspects of mechanical design and electrical control, and simultaneously their algorithms were discussed. Coming to analytical simulations like forward and inverse kinematics, dynamic simulation of the moments of the multibody sy...

A review of exoskeleton-type systems and their key technologies

The exoskeleton-type system is a brand new type of man-machine intelligent system. It fully combines human intelligence and machine power so that machine intelligence and human operator's power are both enhanced. Therefore, it achieves a high-level performance that neither could separately. This paper describes the basic exoskeleton concepts from biological system to man-machine intelligent systems. It is followed by an overview of the development history of exoskeleton-type systems and their two main applications in teleoperation and human power augmentation. Besides the key technologies in exoskeleton-type systems, the research is presented from several viewpoints of the biomechanical design, system structure modelling, cooperation and function allocation, control strategy, and safety evaluation.

Design and Motion Control of a Lower Limb Robotic Exoskeleton

Design, Control and Applications of Mechatronic Systems in Engineering

This chapter presents the results of research work on design, actuator selection and motion control of a lower extremity exoskeleton developed to provide legged mobility to spinal cord injured (SCI) individuals. The exoskeleton has two degrees of freedom per leg. Hip and knee joints are actuated in the sagittal plane by using DC servomotors. Additional effort supplied by user's arms through crutches is defined as user support rate (USR). Experimentally determined USR values are considered in actuator torque computations for achieving a realistic actuator selection. A custom-embedded system is used to control exoskeleton. Reference joint trajectories are determined by using clinical gait analysis (CGA). Three-loop cascade controllers with current, velocity and position feedback are designed for controlling the joint motions of the exoskeleton. A non-linear ARX model is used to determine controller parameters. Overall performance and an assistive effect of WSE-2 are experimentally investigated by conducting tests with a paraplegic patient with T10 complete injury.

Design of a Robotic Exoskeleton Force Multiplier for Upper Limb

International Journal of Mechanical Engineering and Robotics Research, 2020

This researching is based on the design and implementation of a force multiplier exoskeleton for upper limb with two degrees of freedom. This study focuses on a type of current exoskeleton that improves the motor functions of the human body by increasing the strength, speed and physical resistance of the user. The exoskeleton is based on the anthropometry of the Ecuadorian population and human biomechanics for the modeling of the exoskeleton that was based on the mathematical model of its kinematics; in addition, the design was validated with CAE software in which mechanical simulations and analysis were performed of finite element stresses to determine the safety of the system. In the same way, when using inverse kinematic analysis, the non-linear relationship between the position and orientation of the end of the exoskeleton with respect to a reference coordinate system is determined. These parameters were applied in the design of the control system which uses sensors to determine their position and orientation to execute the required movements by means of a joystick. The intention of the exoskeletal device is to be implemented in an industrial work environment, since it can lift and transport loads of up to 120 Newton. 

IJERT-Design of Active Lower Limb Exoskeleton Model to Aid Biomechanical Activities

International Journal of Engineering Research and Technology (IJERT), 2018

https://www.ijert.org/design-of-active-lower-limb-exoskeleton-model-to-aid-biomechanical-activities https://www.ijert.org/research/design-of-active-lower-limb-exoskeleton-model-to-aid-biomechanical-activities-IJERTCONV6IS07059.pdf We present an electromechanical lower limb exoskeleton model that can be used to rehabilitate the lower limb disabled patients or paraplegic patients assisted with caliper. However other types of calipers like fixed leg caliper and ankle or knee caliper may impose a complication in providing normal and complex flexion and extension to the disabled lower limb. Its an electromechanical lower limb exoskeleton model that can be adopted With respect to kinematics and actuation to a wide range of patients. The introduced design allow to compose lower limb exoskeleton with motorized actuation, which will helps in flexion and extension of hip, knee & ankle ventures, The joints can be flexed by synchronization with the motorized actuation .Three different modules are used in this project , An actuator for active support and a controlling unit for controlling the actuation of the whole system and external supporting module to hold the design intact .The external controller is placed on the Hand crutch which indeed provide better stability for the patients using the exoskeleton system .This concept of electromechanical exoskeleton is a feasible low cost design module over the existing fixed knee caliper.