scholarly journals Mechanical Design and Assessment of a Low-Cost 7-DOF Prosthetic Arm for Shoulder Disarticulation

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
José-Alfredo Leal-Naranjo ◽  
Christopher-René Torres-San Miguel ◽  
Marco Ceccarelli ◽  
Horacio Rostro-Gonzalez
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Low Cost ◽  
Wrist Movement ◽  
Dynamic Simulations ◽  
Elbow Movement ◽  
Proper Design ◽  
Spherical Parallel Manipulator ◽  
Printing Techniques

This work presents the design of a low-cost prosthetic device for shoulder disarticulation. A proper design of the mechanisms has been addressed to obtain a prototype that presents 7 degrees of freedom. Shoulder movement is achieved by means of a spherical parallel manipulator, elbow movement is performed by a six-bar mechanism, and the wrist movement is implemented by a spherical parallel manipulator. A set of dynamic simulations was performed in order to assess the functionality of the design. The prototype was built using 3D printing techniques and implementing low-cost actuators. An experimental evaluation was carried out to characterize this device. The result of this work is a prototype that weighs 1350 g that is able to perform movements related to activities of daily living.

scholarly journals Diseño mecánico de un exoesqueleto para rehabilitación de miembro superior

2015 ◽  
Vol 17 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Juan Francisco Ayala Lozano ◽  
Guillermo Urriolagoitia Sosa ◽  
Beatriz Romero Ángeles ◽  
Christopher René Torres San-Miguel ◽  
Luis Antonio Aguilar-Pérez ◽  
...  
Keyword(s):  
Upper Limb ◽  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Low Cost ◽  
Structure Design ◽  
Upper Limb Rehabilitation ◽  
Palabras Clave ◽  
Mexican Patient ◽  
Almost All ◽  
Limb Rehabilitation

<strong>Título en ingles: Mechanical design of an exoskeleton for upper limb rehabilitation</strong><p><strong>Título corto: Diseño mecánico de un exoesqueleto</strong></p><p><strong>Resumen:</strong> El ritmo de vida actual, tanto sociocultural como tecnológico, ha desembocado en un aumento de enfermedades y padecimientos que afectan las capacidades físico-motrices de los individuos. Esto ha originado el desarrollo de prototipos para auxiliar al paciente a recuperar la movilidad y la fortaleza de las extremidades superiores afectadas. El presente trabajo aborda el diseño de una estructura mecánica de un exoesqueleto con 4 grados de libertad para miembro superior. La cual tiene como principales atributos la capacidad de ajustarse a la antropometría del paciente mexicano (longitud del brazo, extensión del antebrazo, condiciones geométricas de la espalda y altura del paciente). Se aplicó el método <em>BLITZ QFD</em> para obtener el diseño conceptual óptimo y establecer adecuadamente las condiciones de carga de servicio. Por lo que, se definieron 5 casos de estudio cuasi-estáticos e implantaron condiciones para rehabilitación de los pacientes. Asimismo, mediante el Método de Elemento Finito (MEF) se analizaron los esfuerzos y deformaciones a los que la estructura está sometida durante la aplicación de los agentes externos de servicio. Los resultados presentados en éste trabajo exhiben una nueva propuesta para la rehabilitación de pacientes con problemas de movilidad en miembro superior. Donde el equipo propuesto permite la rehabilitación del miembro superior apoyado en 4 grados de libertad (tres grados de libertad en el hombro y uno en el codo), el cual es adecuado para realizar terapias activas y pasivas. Asimismo, es un dispositivo que está al alcance de un mayor porcentaje de la población por su bajo costo y fácil desarrollo en la fabricación.</p><p><strong>Palabras clave:</strong> MEF, Blitz QFD, exoesqueletos, diseño mecánico.</p><p><strong>Abstract</strong>: The pace of modern life, both socio-cultural and technologically, has led to an increase of diseases and conditions that affect the physical-motor capabilities of persons. This increase has originated the development of prototypes to help patients to regain mobility and strength of the affected upper limb. This work, deals with the mechanical structure design of an exoskeleton with 4 degrees freedom for upper limb. Which has the capacity to adjust to the Mexican patient anthropometry (arm length, forearm extension, geometry conditions of the back and the patient’s height) BLITZ QFD method was applied to establish the conceptual design and loading service conditions on the structure.  So, 5 quasi-static cases of study were defined and conditions for patient rehabilitation were subjected. Also by applying the finite element method the structure was analyzed due to service loading. The results presented in this work, show a new method for patient rehabilitation with mobility deficiencies in the upper limb. The proposed new design allows the rehabilitation of the upper limb under 4 degrees of freedom (tree degrees of freedom at shoulder and one at the elbow), which is perfect to perform active and passive therapy. Additionally, it is an equipment of low cost, which can be affordable to almost all the country population.</p><p><strong>Key words:</strong> FEM, Blitz QFD, exoskeletons, mechanical design<strong>.</strong></p><p><strong>Recibido:</strong> agosto 20 de 2014   <strong>Aprobado:</strong> marzo 26 de 2015</p>

Design of Robotic Arm Using Delay Based Operation of DC Geared Motors With a Microcontroller

2008 ◽  
Author(s):  
Dilshad A. Sulaiman ◽  
Akash B. Pandey
Keyword(s):  
Degrees Of Freedom ◽  
Material Handling ◽  
Pulse Width Modulation ◽  
Mechanical Design ◽  
Low Cost ◽  
Open Loop ◽  
Infrared Light ◽  
Robotic Arm ◽  
Design And Technology ◽  
Stepper Motors

This paper provides the design of a simple robotic arm for pick and place operations as well as other material handling operations. The movements of the arm are anthropometric i.e. resembling the human arm with respect to degrees of freedom so as to provide a human touch in industrial and space operations. This system operates using controlled motion of DC geared motors along with a microcontroller based system (8051 or PIC based). Use of PWM (Pulse Width Modulation) can be used to control the RPM of DC geared motors. This system has the advantage of being simple and low cost with a varied flexibility of operation. A collective array of sensors viz. voice sensor, infrared light sensors, proximity sensors etc. can be incorporated to form a feedback induced closed loop system. Whereas for tasks of picking and placing at a fixed location from another location the system can be operational at open-loop. The material for the robotic arm can be polypropylene or acrylic or aluminium to reduce weight without compromising on the strength and lifting capacity of the robotic arm, such that the torque of the DC geared motors (actuators) at each joint are sufficient to lift the arm along with the weight at the end effector. Clutch and gear shifting mechanism can be used to increase the degrees of freedom per actuator. The driving circuit mainly consists of the microcontroller and H-bridge drivers using an 8-bit port to control 4 DC geared motors per port simultaneously or one at a time using delay commands. DC geared motors are quite cheaper than stepper motors and RC Servos thus reducing the total cost of the system drastically. Plus being light weight, DC geared motors reduce the total weight of the system. This paper will also throw light on the programming aspects for the microcontroller (8051 or PIC based) along with the compatible flash programmers and HEX code generators. This project will further explain on the approach followed in the mechanical design of the robotic arm (motion, work volume etc.) as well as the possible future applications of the robotic arm. Also the design of the robotic arm on CAD tools like Solidworks will be discussed in brief along with the modeling and simulation of the various links of the arm as well as the whole assembly of the system. With increasing popularity of Automation, robotic arms are the present and future of all industrial operations. Finally the paper concludes on the further improvements in design and technology.

scholarly journals Design of a 4-DOF grounded exoskeletal robot for shoulder and elbow rehabilitation

2020 ◽  
Vol 2 (1) ◽  
pp. 41-65
Author(s):  
Fatih Karadeniz ◽  
Özgür Ege Aydoğan ◽  
Emin Abdullah Kazancı ◽  
Erhan Akdogan
Keyword(s):  
Degrees Of Freedom ◽  
Muscle Activation ◽  
Mechanical Design ◽  
Low Cost ◽  
Neuromuscular Diseases ◽  
Strength Analysis ◽  
Test Results ◽  
Passive Exercise ◽  
Rehabilitation Robots ◽  
Therapeutic Exercises

The number of cerebrovascular and neuromuscular diseases is increasing in parallel with the rising average age of the world’s population. Since the shoulder anatomy is complex, the number of rehabilitation robots for shoulder movements is limited. This paper presents the mechanical design, control, and testing of a 4 degrees of freedom (DOF) grounded upper limb exoskeletal robot. It is capable of four different therapeutic exercises (passive, active assistive, isotonic and isometric). During the mechanical design, the forces to be exposed to the robot were determined and after the design, the system was tested with strength analysis. Also, a low-cost electromyograph device was developed and integrated into the system to measure muscular activation for feedback and instantaneously muscle activation control for the physiotherapist during the therapy. The system can be used for rehabilitation on the shoulder and elbow.  A PID controller for position-controlled exercises were developed. The test results were presented in terms of simulation and the real system for passive exercise. According to the test results, the developed system can perform passive exercise and can be used for other therapeutic exercises as well.

Dynamic Comparison of a 3-Degrees-of-Freedom Parallel Manipulator With Multiple Dry Clearance Joints and With Lubricated Joints

2018 ◽  
Author(s):  
Haodong Zhang ◽  
Xianmin Zhang ◽  
Xuchong Zhang ◽  
Zhenhui Zhan
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Hydrodynamic Forces ◽  
Force Model ◽  
Dynamic Simulations ◽  
Clearance Joints ◽  
Significant Difference ◽  
Prismatic Joints ◽  
Lubricated Joints

This paper compares the dynamic response of a 3-degree-of-freedom (3-DOFs) parallel manipulator with multiple dry clearance joints and with lubricated joints. For this purpose, a methodology developed on Newton–Euler equations is proposed to study lubricated joints in the parallel manipulator, which involves the hydrodynamic forces and impact forces in the constrained equations. Specifically, the hydrodynamic forces are based on the Reynolds’ equation of an infinitely long lubricated joint. Dynamic simulations are presented through the dynamic parameters of a planar parallel manipulator (3-PRR, the underline of the P represents the actuated joint, P and R represents prismatic and revolute pairs respectively), which has six revolute clearance joints and three ideal prismatic joints. The results of the comparison show that the lubricant makes significant difference and greatly improves the dynamic performance of the parallel manipulator with multiple revolute joints. More periodic states are observed from the dynamic behavior of the parallel manipulator with lubricated joints, making the manipulator easier to drive. All results demonstrate the usage of the procedures which contain the hydrodynamic force model of multiple lubricated joints in non-linear DAEs of a 3-DOFs parallel manipulator.

scholarly journals Design, Modeling, and Control of an Autonomous Legged-Wheeled Hybrid Robotic Vehicle with Non-Rigid Joints

2021 ◽  
Vol 11 (13) ◽  
pp. 6116
Author(s):  
Vítor H. Pinto ◽  
Inês N. Soares ◽  
Marco Rocha ◽  
José Lima ◽  
José Gonçalves ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Low Cost ◽  
Communication Strategy ◽  
Test Bed ◽  
Modeling And Control ◽  
Rotational Joint ◽  
Robotic Vehicle ◽  
Rigid Joints ◽  
And Control

This paper presents a legged-wheeled hybrid robotic vehicle that uses a combination of rigid and non-rigid joints, allowing it to be more impact-tolerant. The robot has four legs, each one with three degrees of freedom. Each leg has two non-rigid rotational joints with completely passive components for damping and accumulation of kinetic energy, one rigid rotational joint, and a driving wheel. Each leg uses three independent DC motors—one for each joint, as well as a fourth one for driving the wheel. The four legs have the same position configuration, except for the upper hip joint. The vehicle was designed to be modular, low-cost, and its parts to be interchangeable. Beyond this, the vehicle has multiple operation modes, including a low-power mode. Across this article, the design, modeling, and control stages are presented, as well as the communication strategy. A prototype platform was built to serve as a test bed, which is described throughout the article. The mechanical design and applied hardware for each leg have been improved, and these changes are described. The mechanical and hardware structure of the complete robot is also presented, as well as the software and communication approaches. Moreover, a realistic simulation is introduced, along with the obtained results.

A Novel Shoulder Exoskeleton Robot Using Parallel Actuation and a Passive Slip Interface

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Justin Hunt ◽  
Hyunglae Lee ◽  
Panagiotis Artemiadis
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Glenohumeral Joint ◽  
Translational Motion ◽  
Euler Angle ◽  
Inverse Kinematic ◽  
New Method ◽  
Novel Technologies ◽  
Manipulator Design ◽  
Spherical Parallel Manipulator

This paper presents a five degrees-of-freedom (DoF) low inertia shoulder exoskeleton. This device is comprised of two novel technologies. The first is 3DoF spherical parallel manipulator (SPM), which was developed using a new method of parallel manipulator design. This method involves mechanically coupling certain DoF of each independently actuated linkage of the parallel manipulator in order to constrain the kinematics of the entire system. The second is a 2DoF passive slip interface used to couple the user upper arm to the SPM. This slip interface increases system mobility and prevents joint misalignment caused by the translational motion of the user's glenohumeral joint from introducing mechanical interference. An experiment to validate the kinematics of the SPM was performed using motion capture. The results of this experiment validated the SPM's forward and inverse kinematic solutions through an Euler angle comparison of the actual and command orientations. A computational slip model was created to quantify the passive slip interface response for different conditions of joint misalignment. In addition to offering a low inertia solution for the rehabilitation or augmentation of the human shoulder, this device demonstrates a new method of motion coupling, which can be used to impose kinematic constraints on a wide variety of parallel architectures. Furthermore, the presented device demonstrates a passive slip interface that can be used with either parallel or serial robotic systems.

Analysis of Two Spherical Parallel Manipulators With Hidden Revolute Joints

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Ju Li ◽  
J. Michael McCarthy
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Internal Constraints ◽  
Quadric Surfaces ◽  
Revolute Joints ◽  
Serial Chain ◽  
Point Of Intersection ◽  
Spherical Parallel Manipulator

In this paper, we examine two spherical parallel manipulators (SPMs) constructed with legs that include planar and spherical subchains that combine to impose constraints equivalent to hidden revolute joints. The first has supporting serial chain legs constructed from three revolute joints with parallel axes, denoted R∥R∥R, followed by two revolute joints that have intersecting axes, denoted RR̂. The leg has five degrees-of-freedom and is denoted R∥R∥R-RR̂. Three of these legs can be assembled so the spherical chains all share the same point of intersection to obtain a spherical parallel manipulator denoted as 3-R∥R∥R-RR̂. The second spherical parallel manipulator has legs constructed from three revolute joints that share one point of intersection, denoted RRR̂, and a second pair of revolute joints with axes that intersect in a different point. This five-degree-of-freedom leg is denoted RRR̂-RR̂. The spherical parallel manipulator constructed from these legs is 3-RRR̂-RR̂. We show that the internal constraints of these two types of legs combine to create hidden revolute joints that can be used to analyze the kinematics and singularities of these spherical parallel manipulators. A quaternion formulation provides equations for the quartic singularity varieties some of which decompose into pairs of quadric surfaces which we use to classify these spherical parallel manipulators.

A closed-form solution for the position analysis of a novel fully spherical parallel manipulator

Robotica ◽  
2015 ◽  
Vol 33 (10) ◽  
pp. 2114-2136 ◽  
Author(s):  
Javad Enferadi ◽  
Amir Shahi
Keyword(s):  
Parallel Manipulator ◽  
Closed Form Solution ◽  
Admissible Solution ◽  
Form Solution ◽  
The Other ◽  
Future Research ◽  
Dynamic Simulations ◽  
Coupled Equations ◽  
Position Problem ◽  
Spherical Parallel Manipulator

SUMMARYIn this paper, a novel 3(RPSP)-S fully spherical parallel manipulator (SPM) is introduced. Also, an innovative method based on the geometry of the manipulator is presented for solving the forward position problem of the manipulator. The presented method provides a framework for the future research to solve the forward position problem of the other fully spherical PMs (for examples 3(UPS)-S and 3(RSS)-S). In the proposed method, two coupled trigonometric equations are obtained by utilizing the geometry of the manipulator and Rodrigues' rotation formula. Using Bezout's elimination technique, the two coupled equations lead to a polynomial of degree eight. We show that the polynomial is minimal and optimal. Furthermore, the other method is proposed for selecting an admissible solution of the forward position problem. This algorithm is required to control modeling and dynamic simulations.

Design of Robotic Arm Using Delay Based Operation of DC Geared Motors With a Microcontroller

2008 ◽  
Author(s):  
Dilshad A. Sulaiman ◽  
Akash B. Pandey
Keyword(s):  
Degrees Of Freedom ◽  
Material Handling ◽  
Pulse Width Modulation ◽  
Mechanical Design ◽  
Low Cost ◽  
Open Loop ◽  
Infrared Light ◽  
Robotic Arm ◽  
Design And Technology ◽  
Stepper Motors

This paper provides the design of a simple robotic arm for pick and place operations as well as other material handling operations. The movements of the arm are anthropometric i.e. resembling the human arm with respect to degrees of freedom so as to provide a human touch in industrial and space operations. This system operates using controlled motion of DC geared motors along with a microcontroller based system (8051 or PIC based). Use of PWM (Pulse Width Modulation) can be used to control the RPM of DC geared motors. This system has the advantage of being simple and low cost with a varied flexibility of operation. A collective array of sensors viz. voice sensor, infrared light sensors, proximity sensors etc. can be incorporated to form a feedback induced closed loop system. Whereas for tasks of picking and placing at a fixed location from another location the system can be operational at open-loop. The material for the robotic arm can be polypropylene or acrylic or aluminium to reduce weight without compromising on the strength and lifting capacity of the robotic arm, such that the torque of the DC geared motors (actuators) at each joint are sufficient to lift the arm along with the weight at the end effector. Clutch and gear shifting mechanism can be used to increase the degrees of freedom per actuator. The driving circuit mainly consists of the microcontroller and H-bridge drivers using an 8-bit port to control 4 DC geared motors per port simultaneously or one at a time using delay commands. DC geared motors are quite cheaper than stepper motors and RC Servos thus reducing the total cost of the system drastically. Plus being light weight, DC geared motors reduce the total weight of the system. This paper will also throw light on the programming aspects for the microcontroller (8051 or PIC based) along with the compatible flash programmers and HEX code generators. This project will further explain on the approach followed in the mechanical design of the robotic arm (motion, work volume etc.) as well as the possible future applications of the robotic arm. Also the design of the robotic arm on CAD tools like Solidworks will be discussed in brief along with the modeling and simulation of the various links of the arm as well as the whole assembly of the system. With increasing popularity of Automation, robotic arms are the present and future of all industrial operations. Finally the paper concludes on the further improvements in design and technology.

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