Motion and force control method of 7-DOF cable-driven rehabilitation exoskeleton robot

2018 ◽  
Vol 38 (5) ◽  
pp. 595-605 ◽  
Author(s):  
Wencheng Ni ◽  
Hui Li ◽  
Zhihong Jiang ◽  
Bainan Zhang ◽  
Qiang Huang
Keyword(s):  
Design Methodology ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Body Measurements ◽  
Joint Movement ◽  
Content Type ◽  
Rehabilitation Training ◽  
Exoskeleton Robot ◽  
Training Mode ◽  
Active Rehabilitation

Purpose The purpose of this paper is to design an exoskeleton robot and present a corresponding rehabilitation training method for patients in different rehabilitation stages. Design/methodology/approach This paper presents a lightweight seven-degrees-of-freedom (DOF) cable-driven exoskeleton robot that is wearable and adjustable. After decoupling joint movement caused by a cable-driven mechanism, active rehabilitation training mode and passive rehabilitation training mode are proposed to improve the effect of rehabilitation training. Findings Simulations and experiments have been carried out, and the results validated the feasibility of the proposed mechanism and methods by a fine rehabilitative effect with different persons. Originality/value This paper designed a 7-DOF cable-driven exoskeleton robot that is suitable for patients of different body measurements and proposed the active rehabilitation training mode and passive rehabilitation training mode based on the cable-driven exoskeleton robot.

Application Study on Finger Joint Motion in Rehabilitation Training

2014 ◽  
Vol 644-650 ◽  
pp. 879-883
Author(s):  
Jing Jing Yu
Keyword(s):  
Control Method ◽  
Finger Joint ◽  
Continuous Passive Motion ◽  
Joint Motion ◽  
Joint Movement ◽  
Rehabilitation Training ◽  
Angle Data ◽  
Finger Flexion ◽  
And Control ◽  
Flexion And Extension

In various forms of movement of finger rehabilitation training, Continuous Passive Motion (CPM) of single degree of freedom (1 DOF) has outstanding application value. Taking classic flexion and extension movement for instance, this study collected the joint angle data of finger flexion and extension motion by experiments and confirmed that the joint motion of finger are not independent of each other but there is certain rule. This paper studies the finger joint movement rule from qualitative and quantitative aspects, and the conclusion can guide the design of the mechanism and control method of finger rehabilitation training robot.

A novel active balance assistive control strategy based on virtual stiffness model of XCoM

2019 ◽  
Vol 40 (1) ◽  
pp. 132-142
Author(s):  
Wei Guo ◽  
Shiyin Qiu ◽  
Fusheng Zha ◽  
Jing Deng ◽  
Xin Wang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Design Methodology ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Proof Of Concept ◽  
Disturbing Force ◽  
Content Type ◽  
Exoskeleton Robot ◽  
Stiffness Model ◽  
Virtual Stiffness

PurposeThis paper aims to propose a novel balance-assistive control strategy for hip exoskeleton robot.Design/methodology/approachA hierarchical balance assistive controller based on the virtual stiffness model of extrapolated center of mass (XCoM) is proposed and tested by exoskeleton balance assistive control experiments.FindingsExperiment results show that the proposed controller can accelerate the swing foot chasing XCoM and enlarge the margin of stability.Originality/valueAs a proof of concept, this paper shows the potential for exoskeleton to actively assist human regain balance in sagittal plane when human suffers from a forward or backward disturbing force.

An efficient reformulation of a multiscale method for the eddy current problem

2017 ◽  
Vol 36 (5) ◽  
pp. 1421-1429
Author(s):  
Markus Schöbinger ◽  
Karl Hollaus ◽  
Joachim Schöberl
Keyword(s):  
Eddy Current ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Current Problem ◽  
Multiscale Method ◽  
Content Type ◽  
Eddy Current Problem ◽  
Laminate Thickness ◽  
The Cost ◽  
Laminated Material

Purpose This paper aims to improve the efficiency of a numerical method to treat the eddy current problem on a laminated material, where using a mesh that resolves each individual laminate would be too computationally expensive. Design/methodology/approach The domain is modeled using a coarse mesh that treats the laminated material as a bulk with averaged properties. The fine-structured behavior is recovered by introducing micro-shape functions in the ansatz space. One such method is analyzed to find further model restrictions. Findings By using a special reformulation, it is possible to eliminate the additional degrees of freedom introduced by the multiscale ansatz at the cost of an additional modeling error that decreases with the laminate thickness. Originality/value The paper gives a computationally more efficient approximate variant to a known multiscale method.

General inverse solution of six-degrees-of-freedom serial robots based on the product of exponentials model

2018 ◽  
Vol 38 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Haixia Wang ◽  
Xiao Lu ◽  
Wei Cui ◽  
Zhiguo Zhang ◽  
Yuxia Li ◽  
...  
Keyword(s):  
Design Methodology ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Complex Problem ◽  
Content Type ◽  
Geometrical Properties ◽  
Closed Form Solutions ◽  
Six Degrees Of Freedom ◽  
Serial Robots ◽  
Six Dof

Purpose Developing general closed-form solutions for six-degrees-of-freedom (DOF) serial robots is a significant challenge. This paper thus aims to present a general solution for six-DOF robots based on the product of exponentials model, which adapts to a class of robots satisfying the Pieper criterion with two parallel or intersecting axes among its first three axes. Design/methodology/approach The proposed solution can be represented as uniform expressions by using geometrical properties and a modified Paden–Kahan sub-problem, which mainly adopts the screw theory. Findings A simulation and experiments validated the correctness and effectiveness of the proposed method (general resolution for six-DOF robots based on the product of exponentials model). Originality/value The Rodrigues rotation formula is additionally used to turn the complex problem into a solvable trigonometric function and uniformly express six solutions using two formulas.

scholarly journals Robotic additive manufacturing system for dynamic build orientations

2020 ◽  
Vol 26 (4) ◽  
pp. 659-667
Author(s):  
Nicholas R. Fry ◽  
Robert C. Richardson ◽  
Jordan H. Boyle
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Manufacturing System ◽  
Print Quality ◽  
Orientation Relationships ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Build Orientation

Purpose This paper aims to present a multi-axis additive robot manufacturing system (ARMS) and demonstrate its beneficial capabilities. Design/methodology/approach ARMS was constructed around two robot arms and a fused filament fabrication (FFF) extruder. Quantitative experiments are conducted to investigate the effect of printing at different orientations with respect to gravity, the effect of dynamically changing build orientation with respect to the build tray when printing overhanging features, the effect of printing curved parts using curved, conformal layers. These capabilities are combined to print an integrated demonstrator showing potential practical benefits of the system. Findings Orientation with respect to gravity has no effect on print quality; dynamically changing build orientation allows overhangs up to 90° to be cleanly printed without support structures; printing an arch with conformal layers significantly increases its strength compared to conventional printing. Research limitations/implications The challenge of automatic slicing algorithms has not been addressed for multi-axis printing. It is shown that ARMS could eventually enable printing of fully-functional prototypes with embedded components. Originality/value This work is the first to prove that the surface roughness of an FFF part is independent of print orientation with respect to gravity. The use of two arms creates a novel system with more degrees of freedom than existing multi-axis printers, enabling studies on printing orientation relationships and printing around inserts. It also adds to the emerging body of multi-axis literature by verifying that curved layers improve the strength of an arch which is steeply curved and printed with the nozzle remaining normal to the curvature.

SSVEP-based active control of an upper limb exoskeleton using a low-cost brain–computer interface

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yue Xu ◽  
Qingcong Wu ◽  
Bai Chen ◽  
Xi Chen
Keyword(s):  
Upper Limb ◽  
Visual Stimulation ◽  
Low Cost ◽  
Eeg Signal ◽  
Content Type ◽  
Upper Limb Exoskeleton ◽  
Exoskeleton Robot ◽  
Rehabilitation System ◽  
Training Mode ◽  
Processing Platform

Purpose For the robot-assisted upper limb rehabilitation training process of the elderly with damaged neuromuscular channels and hemiplegic patients, bioelectric signals are added to transform the traditional passive training mode into the active training mode. Design/methodology/approach This paper mainly builds a steady-state visual stimulation interface, an electroencephalography (EEG) signal processing platform and an exoskeleton robot verification platform. The target flashing stimulation blocks provide visual stimulation at the specified position according to the specified frequency and stimulate EEG signals of different frequency bands. The EEG signal-processing platform constructed in this paper removes the noise by using Butterworth band-pass filtering and common average reference filtering on the obtained signals. Further, the features are extracted to identify the volunteer’s active movement intention through the canonical correlation analysis (CCA) method. The classification results are transmitted to the upper limb exoskeleton robot control system, combined with the position and posture of the exoskeleton robot to control the joint motion of robot. Findings Through a large number of experimental studies, the average accuracy of offline recognition of motion intention recognition can reach 86.1%. The control strategy with a three-instruction judgment method reduces the average execution error rate of the entire control system to 6.75%. Online experiments verify the feasibility of the steady-state visual evoked potentials (SSVEP)-based rehabilitation system. Originality/value An EEG signal analysis method based on SSVEP is integrated into the control of an upper limb exoskeleton robot, transforming the traditional passive training mode into the active training mode. The device used to record EEG is of very low cost, which has the potential to promote the rehabilitation system for further widely applications.

From Manhattan to Tenochtitlán: identifying ethical commercial norms

2018 ◽  
Vol 24 (4) ◽  
pp. 435-456 ◽  
Author(s):  
Jason Good ◽  
Paloma Vargas Montes ◽  
Bryan W. Husted ◽  
Blanca López de Mariscal
Keyword(s):  
Sixteenth Century ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Business Models ◽  
Business Practices ◽  
Content Type ◽  
Environmentally Sustainable ◽  
Historical Texts ◽  
Ethical Norms ◽  
Met Expectations

Purpose This paper aims to examine the sixteenth-century Nahua society of central Mexico to answer the question, what commercial ethical norms operated in the sixteenth-century Nahua society? After decades of trying, Western business models and managerial theories have not met expectations in terms of fostering a socially and environmentally sustainable future. Qualitatively different approaches are needed, and one way to find them is to look at business models, norms and practices that operated in societies that were isolated from Western influences. Design/methodology/approach This paper contributes to efforts to find and analyze historical texts that include business practices. In particular, this study uses grounded theory techniques to examine the presence of ethical commercial norms in one of history’s foundational ethnographic texts, The Florentine Codex, a sixteenth-century study of Nahua society. Findings This study identified six commercial ethical norms that structured Nahua commerce: “care for others,” “exercise prudence,” “tell the truth,” “be respectful of others,” “show reverence to the gods” and “be humble.” Confidence in these findings was enhanced by their “qualitative degrees of freedom,” whereby these norms were found to operate in other sectors of Nahua society. Originality/value This study contributes to the literature by demonstrating ethical norms of commerce that can emerge in isolation from Western cultures; providing a rigorous and novel methodology for deriving norms from historical texts; and expanding knowledge of business practices beyond modern Western contexts.

A novel hybrid electromagnetism‐like algorithm for solving the inverse kinematics of robot

2011 ◽  
Vol 38 (4) ◽  
pp. 429-440 ◽  
Author(s):  
Feng Yin ◽  
Yaonan Wang ◽  
Shuning Wei
Keyword(s):  
Heuristic Algorithm ◽  
Hybrid Method ◽  
Minimization Problem ◽  
Inverse Kinematics ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
High Dimensional ◽  
Equivalent Problem ◽  
Content Type ◽  
Iteration Number

PurposeThis paper aims to develop a new real‐time effective method for solving the inverse kinematics (IK) problem, especially for those manipulators with high‐dimensional nonlinear kinematic equations.Design/methodology/approachThe paper transforms the IKs problem into a minimization problem. Then, a novel meta‐heuristic algorithm, called the electromagnetism‐like method (EM), is used to solve this equivalent problem. Moreover, in order to further improve the computational efficiency and accuracy of EM, a hybrid method which combines EM with the Davidon‐Fletcher‐Powell (DFP) method is proposed.FindingsThe results showed that EM is a powerful yet easy algorithm for solving the IKs problem of robot manipulators. Its complexity is independent on the characteristics of the kinematic equations involving dimensionality and the degree of nonlinearity. Moreover, EM can be used as an accompanying algorithm for DFP method to get better precision at a lower iteration number.Originality/valueThe method developed in this paper is a generalized approach that is efficient enough to obtain IK solutions independent of robot geometry and the number of degrees of freedom.

scholarly journals Design of an Active and Passive Control System of Hand Exoskeleton for Rehabilitation

2019 ◽  
Vol 9 (11) ◽  
pp. 2291 ◽  
Author(s):  
Fuhai Zhang ◽  
Legeng Lin ◽  
Lei Yang ◽  
Yili Fu
Keyword(s):  
Control System ◽  
Passive Control ◽  
Control Method ◽  
Human Robot Interaction ◽  
Impedance Method ◽  
Hand Rehabilitation ◽  
Inverse Dynamic ◽  
Rehabilitation Training ◽  
Hand Exoskeleton ◽  
Active Rehabilitation

Aiming at stroke patients’ hand rehabilitation training, we present a hand exoskeleton with both active and passive control modes for neural rehabilitation. The exoskeleton control system is designed as a human–robot interaction control system based on field-programmable gate array (FPGA) and Android mobile terminal with good portability and openness. Passive rehabilitation pattern based on proportional derivative (PD) inverse dynamic control method and active rehabilitation pattern based on impedance method, are established respectively. By the comparison of the threshold value and the force on the fingertip of the exoskeleton from the sensor, the automatic switch between active and passive rehabilitation mode is accomplished. The hand model is built in Android environment that can synchronize the movement of the hand. It can also induce patients to participate in rehabilitation training actively. To verify the proposed control approach, we set up and conduct an experiment to do the passive rehabilitation mode, active rehabilitation mode, and active plus passive mode experimental researches. The experiment results effectively verify the feasibility of the exoskeleton system fulfilling the proposed control strategy.

Three-axes predictive control of autopilot for missile

2017 ◽  
Vol 89 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Celâl Ada ◽  
Ayhan Kural
Keyword(s):  
Predictive Control ◽  
Design Methodology ◽  
Control Method ◽  
Control Effort ◽  
Stochastic Effects ◽  
Content Type ◽  
Modeling Uncertainties ◽  
Zero Degree ◽  
Miss Distance ◽  
Control Methodology

Purpose The purpose of this paper is to present the autopilot design for the missile under various disturbances. Design/methodology/approach In this study, model predictive control (MPC) method has been used for autopilot design for each axis. The aim of autopilot is that to keep the roll angle value around the zero degree and to track pitch/yaw acceleration commands. This three-axes control methodology also takes into consideration the interaction between pitch, yaw and roll motions. Findings The purpose of using MPC method for three-axes of the autopilot is to decrease the control effort and to make the close-loop system insensitive against modeling uncertainties and stochastic effects. Originality/value This study shows that the missile is able to reach to the desired target with good robustness, low control effort and little miss-distance under disturbances such as aerodynamic uncertainties, thrust misalignment and gust affect by using this alternative control method.

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