Comparative analysis of three categories of four-DOFs exoskeleton mechanism based on relative movement offsets

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qiang Cao ◽  
Jianfeng Li ◽  
Mingjie Dong

Purpose The purpose of this paper is to evaluate three categories of four-degrees of freedom (4-DOFs) upper limb rehabilitation exoskeleton mechanisms from the perspective of relative movement offsets between the upper limb and the exoskeleton, so as to provide reference for the selection of exoskeleton mechanism configurations. Design/methodology/approach According to the configuration synthesis and optimum principles of 4-DOFs upper limb exoskeleton mechanisms, three categories of exoskeletons compatible with upper limb were proposed. From the perspective of human exoskeleton closed chain, through reasonable decomposition and kinematic characteristics analysis of passive connective joints, the kinematic equations of three categories exoskeletons were established and inverse position solution method were addressed. Subsequently, three indexes, which can represent the relative movement offsets of human–exoskeleton were defined. Findings Based on the presented position solution and evaluation indexes, the joint displacements and relative movement offsets of the three exoskeletons during eating movement were compared, on which the kinematic characteristics were investigated. The results indicated that the second category of exoskeleton was more suitable for upper limb rehabilitation than the other two categories. Originality/value This paper has a certain reference value for the selection of the 4-DOFs upper extremity rehabilitation exoskeleton mechanism configurations. The selected exoskeleton can ensure the safety and comfort of stroke patients with upper limb dyskinesia during rehabilitation training.

2014 ◽  
Vol 701-702 ◽  
pp. 654-658 ◽  
Author(s):  
Yuan Zhang ◽  
Qiang Liu ◽  
Ji Liang Jiang ◽  
Li Yuan Zhang ◽  
Rui Rui Shen

A new upper limb exoskeleton mechanical structure for rehabilitation train and electric putters were used to drive the upper limb exoskeleton and kinematics simulation was carried. According to the characteristics of upper limb exoskeleton, program control and master - slave control two different ways were presented. Motion simulation analysis had been done by Pro/E Mechanism, the motion data of electric putter and major joints had been extracted. Based on the analysis of the movement data it can effectively guide the electric putter control and analysis upper limb exoskeleton motion process.


Author(s):  
Yanlin Shi ◽  
Qingjin Peng

Conceptual design plays an important role in product development to meet requirements of the product function, cost and other factors. Existing methods of the product conceptual design rely on experience of designers or benchmarking methods to estimate design parameters, which limits the design automation and optimization. This paper improves the benchmarking methods by integrating the kinematics analysis with quality function deployment in design of an upper limb exoskeleton rehabilitation device. Parameters such as velocity, acceleration and displacement of the product are included for rating benchmarking products to evaluate the rehabilitation device based on customer needs. By integrating the benchmarking method and kinematics analysis, products with the best performance can be determined accurately to help designers to improve the existing product or develop a new product. The proposed method is verified in the design of an upper limb rehabilitation device.


Robotica ◽  
2019 ◽  
Vol 37 (12) ◽  
pp. 2073-2086 ◽  
Author(s):  
Amin Zeiaee ◽  
Rana Soltani-Zarrin ◽  
Reza Langari ◽  
Reza Tafreshi

SummaryThis paper studies the problem of optimizing the kinematic structure of an eight degree-of-freedom upper-limb rehabilitation exoskeleton. The objective of optimization is achieving minimum volume and maximum dexterity in the workspace of daily activities specified by a set of upper-arm configurations. To formulate the problem, a new index is proposed for effective characterization of kinematic dexterity for wearable robots. Additionally, a set of constraints are defined to ensure that the optimal design can cover the desired workspace of the exoskeleton, while singular configurations and physical interferences are avoided. The formulated multi-objective optimization problem is solved using an evolutionary algorithm (Non-dominated Sorting Genetic Algorithm II) and the weighted sum approach. Among the resulted optimal points, the point with least sensitivity with respect to the variations of design variables is chosen as the final design.


2019 ◽  
Vol 39 (4) ◽  
pp. 715-726
Author(s):  
Leiyu Zhang ◽  
Jianfeng Li ◽  
Shuting Ji ◽  
Peng Su ◽  
Chunjing Tao ◽  
...  

Purpose Upper-limb joint kinematics are highly complex and the kinematics of rehabilitation exoskeletons fail to reproduce them, resulting in hyperstaticity and human–machine incompatibility. The purpose of this paper is to design and develop a compatible exoskeleton robot (Co-Exos II) to address these problems. Design/methodology/approach The configuration synthesis of Co-Exos II is completed using advanced mechanism theory. A compatible configuration is selected and four passive joints are introduced into the connecting interfaces based on optimal configuration principles. A Co-Exos II prototype with nine degrees of freedom (DOFs) is developed and still owns a compact structure and volume. A new approach is presented to compensate the vertical glenohumeral (GH) movements. Co-Exos II and the upper arm are simplified as a guide-bar mechanism at the elevating plane. The theoretical displacements of passive joints are calculated by the kinematic model of the shoulder loop. The compatible experiments are completed to measure the kinematics of passive joints. Findings The compatible configuration of the passive joints can effectively reduce the gravity influences of the exoskeleton device and the upper extremities. The passive joints exhibit excellent compensation effect for the GH joint movements by comparing the theoretical and measured results. Passive joints can compensate for most GH movements, especially vertical movements. Originality/value Co-Exos II possesses good human–machine compatibility and wearable comfort for the affected upper limbs. The proposed compensation method is convenient to therapists and stroke patients during the rehabilitation trainings.


2013 ◽  
Vol 572 ◽  
pp. 619-623 ◽  
Author(s):  
Lan Wang ◽  
Zheng Qian Yin ◽  
Yuan Hang Sun

Based on the analysis of the methods for upper limb rehabilitation training, an anthropomorphic upper-limb exoskeleton was developed. Anatomical and physiological characteristics and upper limb joint ranges of motion are also considered. The rehabilitation robot is achieved by 4 single-axis revolute joints which are shoulder abduction-adduction (abd-add), shoulder flexion-extension (flx-ext), elbow flx-ext and wrist flx-ext. Kinematics and dynamics analysis of the rehabilitation robot are made. The passive rehabilitation mode and active rehabilitation mode are researched, and the result of experenment is shown that the robot can finish the rehabilitation task well.


2019 ◽  
Vol 141 ◽  
pp. 14-39 ◽  
Author(s):  
Jianfeng Li ◽  
Qiang Cao ◽  
Chunzhao Zhang ◽  
Chunjing Tao ◽  
Run Ji

ROBOT ◽  
2011 ◽  
Vol 33 (3) ◽  
pp. 307-313 ◽  
Author(s):  
Baoguo XU ◽  
Si PENG ◽  
Aiguo SONG

ROBOT ◽  
2012 ◽  
Vol 34 (5) ◽  
pp. 539 ◽  
Author(s):  
Lizheng PAN ◽  
Aiguo SONG ◽  
Guozheng XU ◽  
Huijun LI ◽  
Baoguo XU

Robotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Ferdaws Ennaiem ◽  
Abdelbadiâ Chaker ◽  
Juan Sebastián Sandoval Arévalo ◽  
Med Amine Laribi ◽  
Sami Bennour ◽  
...  

This paper deals with the design of an optimal cable-driven parallel robot (CDPR) for upper limb rehabilitation. The robot’s prescribed workspace is identified with the help of an occupational therapist based on three selected daily life activities, which are tracked using a Qualisys motion capture system. A preliminary architecture of the robot is proposed based on the analysis of the tracked trajectories of all the activities. A multi-objective optimization process using the genetic algorithm method is then performed, where the cable tensions and the robot size are selected as the objective functions to be minimized. The cables tensions are bounded between two limits, where the lower limit ensures a positive tension in the cables at all times and the upper limit represents the maximum torque of the motor. A sensitivity analysis is then performed using the Monte Carlo method to yield the optimal design selected out of the non-dominated solutions, forming the obtained Pareto front. The robot with the highest robustness toward the disturbances is identified, and its dexterity and elastic stiffness are calculated to investigate its performance.


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